AMDGPU: Remove optnone from a test

It's not clear why the test had this. I'm unable to break the original
case with the original patch reverted with or without optnone.

This avoids a failure in a future commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375321 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed