RuntimeDyldMachOAArch64.h: Fix a warning. [-Wunused-variable]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213710 91177308-0d34-0410-b5e6-96231b3b80d8
Trailing whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213711 91177308-0d34-0410-b5e6-96231b3b80d8