mshr: Prevent assertion misfire during reset

Created by: paulsc96

While the cache is held in reset, the one_command_assert assertion in hpdcache_mshr will always fail, raising a false-positive error any time the cache is being reset:

# ** Error: MSHR: ack with concurrent alloc or check

This should not happen as the reported error is not an actual issue. Furthermore, it presents a problem for testing setups designed to fail on assertion failures, as any meaningful simulation will trigger this assertion.

The proposed fix masks the assertion during reset with the disable iff clause.