s3_cache.py: fix name in USAGE message

test-infra/s3_cache.py

@@ -83,7 +83,7 @@ if __name__ == '__main__':
     #   AWS_SECRET_ACCESS_KEY -- AWS Secret Access Key
     argv.pop(0)
     if len(argv) != 4:
-        raise SystemExit("USAGE: node_modules_cache.py <download | upload> <friendly name> <dependencies file> <directory>")
+        raise SystemExit("USAGE: s3_cache.py <download | upload> <friendly name> <dependencies file> <directory>")
     mode, friendly_name, dependencies_file, directory = argv
 
     conn = S3Connection()