Make gcl and git-cl don't throw when a vim user does :cg

That's just noise for the maintainer.

R=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6985002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@84803 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/git_cl.py b/git_cl.py
index 9e1124c..5cf2580 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -842,7 +842,10 @@
       # Msysgit requires the usage of 'env' to be present.
       cmd = 'env ' + cmd
     # shell=True to allow the shell to handle all forms of quotes in $EDITOR.
-    subprocess.check_call(cmd, shell=True)
+    try:
+      subprocess.check_call(cmd, shell=True)
+    except subprocess.CalledProcessError, e:
+      DieWithError('Editor returned %d' % e.returncode)
     fileobj = open(filename)
     text = fileobj.read()
     fileobj.close()