Revert "[include-fixer] Don't throw exception when parsing unknown arguments in vim script."

This reverts commit r302934. It's wrong, edits the wrong file and was
committed without review.

llvm-svn: 303242

clang-tools-extra/include-fixer/find-all-symbols/tool/run-find-all-symbols.py

@@ -75,7 +75,7 @@ def main():
                       help='path used to read a compilation database.')
   parser.add_argument('-saving-path', default='./find_all_symbols_db.yaml',
                       help='result saving path')
-  args, _ = parser.parse_known_args()
+  args = parser.parse_args()
 
   db_path = 'compile_commands.json'