regmap: replace kzalloc with kcalloc

Replace kzalloc with specialized function kcalloc when the size is
a multiplication of : number * sizeof

Signed-off-by: lixiubo <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 56486d9..3b6cfede 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -366,8 +366,9 @@
 	if (!rbnode->block)
 		goto err_free;
 
-	rbnode->cache_present = kzalloc(BITS_TO_LONGS(rbnode->blklen) *
-		sizeof(*rbnode->cache_present), GFP_KERNEL);
+	rbnode->cache_present = kcalloc(BITS_TO_LONGS(rbnode->blklen),
+					sizeof(*rbnode->cache_present),
+					GFP_KERNEL);
 	if (!rbnode->cache_present)
 		goto err_free_block;