49addc5755
With some recent busdma refactoring, sometimes it happens that a sync op gets called when bus_dmamap_load() never got called, which results in a spurious warning about a map mismatch when no sync operations will actually happen anyway. Now the check is done only if a sync operation is actually performed, and the result of the check is a panic, not just a printf. Reviewed by: cognet (who prevented me from donning a point hat)