Revert "[llvm-objdump] Add warning messages if disassembly + source for problematic inputs"

This reverts r367284 (git commit b1cbe51b).
My changes to LLVMSymbolizer caused a test to fail:
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-lnt/builds/29488

llvm-svn: 367286