MCObjectFileInfo.cpp: Fix a couple of possible typo(s), s/DwarfPub/DwarfGnuPub/, in r190344.

XFAIL can be removed. (in r190374)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190386 91177308-0d34-0410-b5e6-96231b3b80d8