cbuildbot_config_unittest: Fix path to config_dump.json in assertion message

BUG=none
TEST=none

Change-Id: I47cc2200913ce77882f727ac705f89c1a192f7b2
Reviewed-on: https://chromium-review.googlesource.com/203105
Commit-Queue: Gaurav Shah <gauravsh@chromium.org>
Tested-by: Gaurav Shah <gauravsh@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
diff --git a/cbuildbot/cbuildbot_config_unittest.py b/cbuildbot/cbuildbot_config_unittest.py
index 671a482..2a46d1a 100755
--- a/cbuildbot/cbuildbot_config_unittest.py
+++ b/cbuildbot/cbuildbot_config_unittest.py
@@ -38,7 +38,7 @@
     self.assertTrue(
         new_dump == old_dump, 'config_dump.json does not match the '
         'configs defined in cbuildbot_config.py. Run '
-        'bin/cbuildbot_view_config -d --pretty > buildbot/config_dump.json')
+        'bin/cbuildbot_view_config -d --pretty > cbuildbot/config_dump.json')
 
 
 class ConfigPickleTest(cros_test_lib.TestCase):