ios: fix path to the test app

scripts/slave/recipes/ios/unified_builder_tester.expected/multiple_failures.json

 [
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/host_info.py",
       "--json-file",
       "/path/to/tmp/json"
     ],
     "name": "host and tools info",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br />OS X 1.2.3, Xcode 6.7.8 (5D342509a)@@@",
@@ skipping 245 matching lines @@
       "-sdk",
       "iphonesimulator7.1"
     ],
     "cwd": "[BUILDER_CACHE]/ios/src/xcodebuild",
     "name": "compile"
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/run.py",
       "--app",
-      "[SLAVE_BUILD]/src/xcodebuild/Debug-iphonesimulator/fake tests 1.app",
+      "[BUILDER_CACHE]/ios/src/xcodebuild/Debug-iphonesimulator/fake tests 1.app",
       "--json_file",
       "/path/to/tmp/json",
       "--iossim",
       "[SLAVE_BUILD]/src/xcodebuild/ninja-iossim/Debug/iossim",
       "--platform",
       "fake device",
       "--version",
       "8.1"
     ],
     "name": "fake tests 1 (fake device iOS 8.1)",
@@ skipping 13 matching lines @@
       "@@@STEP_LOG_LINE@fake log@fake log line 1@@@",
       "@@@STEP_LOG_LINE@fake log@fake log line 2@@@",
       "@@@STEP_LOG_END@fake log@@@",
       "@@@STEP_LINK@fake URL text@fake URL@@@"
     ]
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/run.py",
       "--app",
-      "[SLAVE_BUILD]/src/xcodebuild/Debug-iphonesimulator/fake tests 2.app",
+      "[BUILDER_CACHE]/ios/src/xcodebuild/Debug-iphonesimulator/fake tests 2.app",
       "--json_file",
       "/path/to/tmp/json",
       "--iossim",
       "[SLAVE_BUILD]/src/xcodebuild/ninja-iossim/Debug/iossim",
       "--platform",
       "fake device",
       "--version",
       "8.1"
     ],
     "name": "fake tests 2 (fake device iOS 8.1)",
@@ skipping 15 matching lines @@
       "@@@STEP_LOG_LINE@fake log@fake log line 2@@@",
       "@@@STEP_LOG_END@fake log@@@",
       "@@@STEP_LINK@fake URL text@fake URL@@@",
       "@@@STEP_FAILURE@@@"
     ]
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/run.py",
       "--app",
-      "[SLAVE_BUILD]/src/xcodebuild/Debug-iphonesimulator/fake tests 3.app",
+      "[BUILDER_CACHE]/ios/src/xcodebuild/Debug-iphonesimulator/fake tests 3.app",
       "--json_file",
       "/path/to/tmp/json",
       "--iossim",
       "[SLAVE_BUILD]/src/xcodebuild/ninja-iossim/Debug/iossim",
       "--platform",
       "fake device",
       "--version",
       "8.1"
     ],
     "name": "fake tests 3 (fake device iOS 8.1)",
@@ skipping 15 matching lines @@
       "@@@STEP_LOG_LINE@fake log@fake log line 2@@@",
       "@@@STEP_LOG_END@fake log@@@",
       "@@@STEP_LINK@fake URL text@fake URL@@@",
       "@@@STEP_FAILURE@@@"
     ]
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/run.py",
       "--app",
-      "[SLAVE_BUILD]/src/xcodebuild/Debug-iphonesimulator/fake tests 4.app",
+      "[BUILDER_CACHE]/ios/src/xcodebuild/Debug-iphonesimulator/fake tests 4.app",
       "--json_file",
       "/path/to/tmp/json",
       "--iossim",
       "[SLAVE_BUILD]/src/xcodebuild/ninja-iossim/Debug/iossim",
       "--platform",
       "fake device",
       "--version",
       "8.1"
     ],
     "name": "fake tests 4 (fake device iOS 8.1)",
@@ skipping 13 matching lines @@
       "@@@STEP_LOG_LINE@fake log@fake log line 1@@@",
       "@@@STEP_LOG_LINE@fake log@fake log line 2@@@",
       "@@@STEP_LOG_END@fake log@@@",
       "@@@STEP_LINK@fake URL text@fake URL@@@"
     ]
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/run.py",
       "--app",
-      "[SLAVE_BUILD]/src/xcodebuild/Debug-iphonesimulator/fake tests 5.app",
+      "[BUILDER_CACHE]/ios/src/xcodebuild/Debug-iphonesimulator/fake tests 5.app",
       "--json_file",
       "/path/to/tmp/json",
       "--iossim",
       "[SLAVE_BUILD]/src/xcodebuild/ninja-iossim/Debug/iossim",
       "--platform",
       "fake device",
       "--version",
       "8.1"
     ],
     "name": "fake tests 5 (fake device iOS 8.1)",
@@ skipping 15 matching lines @@
       "@@@STEP_LOG_LINE@fake log@fake log line 2@@@",
       "@@@STEP_LOG_END@fake log@@@",
       "@@@STEP_LINK@fake URL text@fake URL@@@",
       "@@@STEP_EXCEPTION@@@"
     ]
   },
   {
     "cmd": [
       "RECIPE_PACKAGE_REPO[build]/scripts/slave/ios/run.py",
       "--app",
-      "[SLAVE_BUILD]/src/xcodebuild/Debug-iphonesimulator/fake tests 6.app",
+      "[BUILDER_CACHE]/ios/src/xcodebuild/Debug-iphonesimulator/fake tests 6.app",
       "--json_file",
       "/path/to/tmp/json",
       "--iossim",
       "[SLAVE_BUILD]/src/xcodebuild/ninja-iossim/Debug/iossim",
       "--platform",
       "fake device",
       "--version",
       "8.1"
     ],
     "name": "fake tests 6 (fake device iOS 8.1)",
@@ skipping 16 matching lines @@
       "@@@STEP_LINK@fake URL text@fake URL@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "Failed fake tests 2 (fake device iOS 8.1), fake tests 3 (fake device iOS 8.1), fake tests 5 (fake device iOS 8.1).",
     "recipe_result": null,
     "status_code": 1
   }
 ]