Add setlocal so {cpplin,gcl}.bat don't repeatedly add \depot_tools to %PATH%.

Review URL: http://codereview.chromium.org/201062

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@25751 0039d316-1c4b-4281-b951-d872f2087c98

cpplint.bat

 @echo off
+setlocal
 :: This is required with cygwin only.
 PATH=%~dp0;%PATH%
 call python "%~dp0cpplint.py" %*

gcl.bat

 @echo off
+setlocal
 :: This is required with cygwin only.
 PATH=%~dp0;%PATH%
 call python "%~dp0gcl.py" %*