staging: greybus: light: fix attributes allocation

Fix allocation of attributes with the correct size, this also fix smatch
warning:

drivers/staging/greybus/light.c:293 channel_attr_groups_set()
warn: double check that we're allocating correct size: 8 vs 16
Signed-off-by: NRui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/greybus/light.c

@@ -290,8 +290,7 @@ static int channel_attr_groups_set(struct gb_channel *channel,
 		return 0;
 
 	/* Set attributes based in the channel flags */
-	channel->attrs = kcalloc(size + 1, sizeof(**channel->attrs),
-				 GFP_KERNEL);
+	channel->attrs = kcalloc(size + 1, sizeof(*channel->attrs), GFP_KERNEL);
 	if (!channel->attrs)
 		return -ENOMEM;
 	channel->attr_group = kcalloc(1, sizeof(*channel->attr_group),