slab: Remove unnecessary call to compound_head() in alloc_from_pcs()

Each page knows which node it belongs to, so there's no need to
convert to a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20251124142329.1691780-1-willy@infradead.org
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

Author: Matthew Wilcox (Oracle)

mm/slub.c

@@ -5149,7 +5149,7 @@ void *alloc_from_pcs(struct kmem_cache *s, gfp_t gfp, int node)
 		 * be false because of cpu migration during an unlocked part of
 		 * the current allocation or previous freeing process.
 		 */
-		if (folio_nid(virt_to_folio(object)) != node) {
+		if (page_to_nid(virt_to_page(object)) != node) {
 			local_unlock(&s->cpu_sheaves->lock);
 			return NULL;
 		}