gn: Remove another obsolete comment about gyp command from command_check.cc.

Forgot to do this in r271968 - https://codereview.chromium.org/296153002

BUG=None
TEST=None
TBR=scottmg@chromium.org

Review URL: https://codereview.chromium.org/299203004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272581 0039d316-1c4b-4281-b951-d872f2087c98

tools/gn/command_check.cc

@@ -20,7 +20,6 @@ const char kCheck_Help[] =
     "\n"
     "  See \"gn help\" for the common command-line switches.\n";
 
-// Note: partially duplicated in command_gyp.cc.
 int RunCheck(const std::vector<std::string>& args) {
   // Deliberately leaked to avoid expensive process teardown.
   Setup* setup = new Setup();