Summary:
I just realized that when we run parallel valgrind we actually don't run the parallel tests under valgrind (we run the normally)
This patch make sure that we run both parallel and non-parallel tests with valgrind
Test Plan: DISABLE_JEMALLOC=1 make valgrind_check -j64
Reviewers: andrewkr, yiwu, lightmark, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D62469