slub: Remove unnecessary page NULL check

In commit 4d7868e6(slub: Do not dereference NULL pointer in node_match)
had added check for page NULL in node_match.  Thus, it is not needed
to check it before node_match, remove it.
Acked-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NLibin <huawei.libin@huawei.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

mm/slub.c

@@ -2386,7 +2386,7 @@ static __always_inline void *slab_alloc_node(struct kmem_cache *s,
 
 	object = c->freelist;
 	page = c->page;
-	if (unlikely(!object || !page || !node_match(page, node)))
+	if (unlikely(!object || !node_match(page, node)))
 		object = __slab_alloc(s, gfpflags, node, addr, c);
 
 	else {