cpumask: avoid deprecated function in mm/slab.c

These days we use cpumask_empty() which takes a pointer.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Christoph Lameter <cl@linux-foundation.org>

mm/slab.c

@@ -1132,7 +1132,7 @@ static void __cpuinit cpuup_canceled(long cpu)
 		if (nc)
 			free_block(cachep, nc->entry, nc->avail, node);
 
-		if (!cpus_empty(*mask)) {
+		if (!cpumask_empty(mask)) {
 			spin_unlock_irq(&l3->list_lock);
 			goto free_array_cache;
 		}