mm/slab_common: use helper function is_power_of_2()

Use helper function is_power_of_2() to check if KMALLOC_MIN_SIZE is power
of two. Minor readability improvement.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20220217091609.8214-1-linmiaohe@huawei.com

mm/slab_common.c

@@ -807,7 +807,7 @@ void __init setup_kmalloc_cache_index_table(void)
 	unsigned int i;
 
 	BUILD_BUG_ON(KMALLOC_MIN_SIZE > 256 ||
-		(KMALLOC_MIN_SIZE & (KMALLOC_MIN_SIZE - 1)));
+		!is_power_of_2(KMALLOC_MIN_SIZE));
 
 	for (i = 8; i < KMALLOC_MIN_SIZE; i += 8) {
 		unsigned int elem = size_index_elem(i);