integration: add some debugging to test_drop_state
integration: add some debugging to test_drop_state

Summary:
This test is flaking very often but due to the result not being displayed this
make the test quite hard to debug. Let's add a small print to better understand
what is returned from Watchman

Reviewed By: kmancini

Differential Revision: D38136924

fbshipit-source-id: 4d2cd78b740bf796c54cf2ddea5b6fa32beaa01a

facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman