[compiler-rt] Fix broken unittest on win64

Summary:
This is an other tentative to fix:
https://reviews.llvm.org/D22588

It's less clever, but should work.

Turn out there is not an easy way to write a portable print
for a pointer in lowercase without the prefix 0x.

Reviewers: rnk

Subscribers: llvm-commits, wang0109, kubabrecka, chrisha

Differential Revision: https://reviews.llvm.org/D22606

llvm-svn: 276286