git-clang-format: Remove trailing whitespace in docstring. NFC.

[aheejin]

I can't find the option of showing whitespace changes in Phabricator so I can't see it, but I'm always in favor of removing trailing whitespaces :D

clang/tools/clang-format/git-clang-format

 #!/usr/bin/env python
 #
 #===- git-clang-format - ClangFormat Git Integration ---------*- python -*--===#
 #
 # Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 #
 #===------------------------------------------------------------------------===#
 
-r"""                                                                             
-clang-format git integration                                                     
-============================                                                     
-                                                                                 
-This file provides a clang-format integration for git. Put it somewhere in your  
-path and ensure that it is executable. Then, "git clang-format" will invoke      
-clang-format on the changes in current files or a specific commit.               
-                                                                                 
-For further details, run:                                                        
-git clang-format -h                                                              
-                                                                                 
-Requires Python 2.7 or Python 3                                                  
-"""               
+r"""
+clang-format git integration
+============================
+This file provides a clang-format integration for git. Put it somewhere in your
+path and ensure that it is executable. Then, "git clang-format" will invoke
+clang-format on the changes in current files or a specific commit.
+For further details, run:
+git clang-format -h
+Requires Python 2.7 or Python 3
+"""
 
 from __future__ import absolute_import, division, print_function
 import argparse
 import collections
 import contextlib
 import errno
 import os
 import re