slub: use alloc_pages_node() in alloc_slab_page()

For no apparent reason, we were open-coding alloc_pages_node() in this
function.

Link: https://lkml.kernel.org/r/20231228085748.1083901-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Matthew Wilcox (Oracle)

mm/slub.c

@@ -1877,11 +1877,7 @@ static inline struct slab *alloc_slab_page(gfp_t flags, int node,
 	struct slab *slab;
 	unsigned int order = oo_order(oo);
 
-	if (node == NUMA_NO_NODE)
-		folio = (struct folio *)alloc_pages(flags, order);
-	else
-		folio = (struct folio *)__alloc_pages_node(node, flags, order);
-
+	folio = (struct folio *)alloc_pages_node(node, flags, order);
 	if (!folio)
 		return NULL;