Fix path warning test.

sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path_test.dart

Index: sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path_test.dart
diff --git a/sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path.dart b/sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path_test.dart
similarity index 85%
rename from sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path.dart
rename to sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path_test.dart
index 3b73d25dd5fd612f6da5bdb0ec795307e45824b7..31b466020925f2cf84f57e77937b07c5d9f9003a 100644
--- a/sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path.dart
+++ b/sdk/lib/_internal/pub_generated/test/global/binstubs/warns_if_not_on_path_test.dart
@@ -7,7 +7,7 @@ main() {
     servePackages((builder) {
       builder.serve("foo", "1.0.0", pubspec: {
         "executables": {
-          "script": null
+          "some-dart-script": "script"
         }
       },
           contents: [
@@ -15,6 +15,6 @@ main() {
     });
     schedulePub(
         args: ["global", "activate", "foo"],
-        output: contains("is not on your path"));
+        error: contains("is not on your path"));
   });
 }