[llvm-objdump] Properly print MachO aarch64 addend relocations

Previously such relocations fell into the last case for local
symbols, using the relocation addend as symbol index, leading to
a crash.

Differential Revision: https://reviews.llvm.org/D35239

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307927 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed