AMDGPU: Fix bug 26659.

Fix checking the same instruction twice instead of the
second branch that uses vccz. I don't think this matters
currently because s_branch_vccnz is always used currently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262457 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed