Fix a regression introduced in r114262, cwd must be a named argument to subprocess2.Popen().

Not sure why pylint didn't catch it. :/

TBR=dpranke@chromium.org
BUG=
TEST=


Review URL: http://codereview.chromium.org/8937010

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@114270 0039d316-1c4b-4281-b951-d872f2087c98

scm.py

@@ -226,7 +226,7 @@ class GIT(object):
     # pipe at a time.
     # The -100 is an arbitrary limit so we don't search forever.
     cmd = ['git', 'log', '-100', '--pretty=medium']
-    proc = subprocess2.Popen(cmd, cwd, stdout=subprocess2.PIPE)
+    proc = subprocess2.Popen(cmd, cwd=cwd, stdout=subprocess2.PIPE)
     url = None
     for line in proc.stdout:
       match = git_svn_re.match(line)