[AMDGPU] Fix incorrect hazard mitigation

[AMDGPU] Fix incorrect hazard mitigation

GCNHazardRecognizer::fixVcmpxExecWARHazard() mitigates a specific hazard
by inserting a wait on sa_sdst==0 if such a wait isn't already present.
Unfortunately, the check for an existing wait incorrectly checks for one
that doesn't actually care about sa_sdst itself, but requires that no
other counters are waited for.

Once the check is performed correctly, a lit test needs to be updated,
since it is currently testing for the incorrect behaviour.

Differential Revision: https://reviews.llvm.org/D154438