Change the test case file to use FileCheck instead of grep. NFC.
Change by Ankur Garg.

Differential Revision: http://reviews.llvm.org/D6382


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222740 91177308-0d34-0410-b5e6-96231b3b80d8