Revert "Fix file.copy recipe_module to not fail if files are already equal."

scripts/slave/recipes/syzygy/continuous.expected/full_master_client_syzygy_Syzygy_Debug.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\kill_processes.py"
     ],
     "name": "taskkill"
   },
   {
@@ skipping 113 matching lines @@
       "@@@STEP_LOG_LINE@python.inline@from common import chromium_utils # Error? See https://crbug.com/584783.@@@",
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@chromium_utils.RemoveFilesWildcards(sys.argv[1], root=sys.argv[2])@@@",
       "@@@STEP_LOG_END@python.inline@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
-      "\nimport shutil\nimport sys\n# Apparently, shutil.copy fails if files are binary-equal on *nix OSes.\n# See http://crbug.com/636168#c8.\nif hasattr(shutil, '_samefile'):\n  if shutil._samefile(sys.argv[1], sys.argv[2]):\n    sys.exit(0)\nshutil.copy(sys.argv[1], sys.argv[2])\n",
+      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
       "[SLAVE_BUILD]\\src\\syzygy\\unittests.gypi",
       "/path/to/tmp/"
     ],
     "name": "read_unittests_gypi"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\runtest.py",
@@ skipping 75 matching lines @@
     "~followup_annotations": [
       "@@@STEP_LINK@archive@https://syzygy-archive.commondatastorage.googleapis.com/index.html?path=builds/metrics/f27fede2220bcd326aee3e86ddfd4ebd0fe58cb9/debug.csv/@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]