Don't use plain %x to print pointer values. I had changed it from %p

Don't use plain %x to print pointer values. I had changed it from %p
since %p isn't formatted consistently, but obviously plain %x is wrong.
PRIxPTR with a cast to uintptr_t would work here, but that requires
inconvenient build-system changes. %lu works on all current and
foreseable future hosts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60616 91177308-0d34-0410-b5e6-96231b3b80d8