[SCEV][NFC] Remove duplication of isLoopInvariant code

Replace two places that duplicate the code of isLoopInvariant method with
the invocation of this method.

Differential Revision: https://reviews.llvm.org/D33313


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303336 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed