flimflam: Fix shill debug level.

BUG=None
TEST=Run cellular_Smoke and verify that shill logs at verbose level 4.

Change-Id: Ieaac9e5dd721553848bc14ee877cd98cc2631e21
Reviewed-on: https://gerrit.chromium.org/gerrit/34586
Commit-Ready: Ben Chan <benchan@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
diff --git a/test/flimflam.py b/test/flimflam.py
index ccfb6b1..7ac0383 100644
--- a/test/flimflam.py
+++ b/test/flimflam.py
@@ -331,7 +331,7 @@
     def SetDebugTags(self, taglist):
         try:
             self.manager.SetDebugTags(taglist)
-            self.SetDebugLevel(4)
+            self.SetDebugLevel(-4)
         except dbus.exceptions.DBusException, error:
             if error.get_dbus_name() not in [
               "org.freedesktop.DBus.Error.UnknownMethod" ]: