Update docs for git usage

chromium-os BUG=1189

Review URL: http://codereview.chromium.org/551002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@36129 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/scm.py b/scm.py
index 0fc5cba..2ec5825 100644
--- a/scm.py
+++ b/scm.py
@@ -101,7 +101,7 @@
 
     Args:
       args: A sequence of command line parameters to be passed.
-      in_directory: The directory where svn is to be run.
+      in_directory: The directory where git is to be run.
       print_messages: Whether to print status messages to stdout about
         which commands are being run.
       print_stdout: Whether to forward program's output to stdout.