mesa: consistantly use mesa memory-functions in gallium state tracker

Use _mesa_malloc(), _mesa_free(), etc everywhere, not malloc(), free(), etc.
Still using CALLOC_STRUCT() at this point.

src/mesa/state_tracker/st_cb_queryobj.c

@@ -87,7 +87,7 @@ st_DeleteQuery(GLcontext *ctx, struct gl_query_object *q)
       stq->pq = NULL;
    }
 
-   FREE(stq);
+   _mesa_free(stq);
 }