[AMDGPU] Revert "[AMDGPU] Add options for waitcnt pass debugging; add instr count in debug output."

Patch caused a buildbot failure; arg; http://lab.llvm.org:8011/builders/lld-x86_64-darwin13/builds/17373/s\
teps/build_Lld/logs/stdio :
        /Users/buildslave/as-bldslv9/lld-x86_64-darwin13/llvm.src/lib/Target/AMDGPU/SIInsertWaitcnts.cpp:1563:18: error: unused variable 'InstCnt' [-Werror,-Wunused-variable]
          static int32_t InstCnt = 0;
                                              "
This reverts commit 4f4a7d61e306b67044d9f16bc2016fee806bc2cc.

llvm-svn: 323791