Make gclient_scm_test much more silent

gclient_utils.py

Index: gclient_utils.py
diff --git a/gclient_utils.py b/gclient_utils.py
index 122e81a21adaa5a6194e9ed60dcf3ee2bfb4f3f7..d2ba580c11739d68e40543038102f18b6ca9e523 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -36,7 +36,7 @@ class CheckCallError(OSError, Error):
   """CheckCall() returned non-0."""
   def __init__(self, command, cwd, returncode, stdout, stderr=None):
     OSError.__init__(self, command, cwd, returncode, stdout, stderr)
-    Error.__init__(self)
+    Error.__init__(self, command)
     self.command = command
     self.cwd = cwd
     self.returncode = returncode