video/uvc: use memweight()

Use memweight() to count the total number of bits set in memory area.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/media/video/uvc/uvc_ctrl.c

@@ -2083,7 +2083,7 @@ int uvc_ctrl_init_device(struct uvc_device *dev)
 	/* Walk the entities list and instantiate controls */
 	list_for_each_entry(entity, &dev->entities, list) {
 		struct uvc_control *ctrl;
-		unsigned int bControlSize = 0, ncontrols = 0;
+		unsigned int bControlSize = 0, ncontrols;
 		__u8 *bmControls = NULL;
 
 		if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT) {
@@ -2101,8 +2101,7 @@ int uvc_ctrl_init_device(struct uvc_device *dev)
 		uvc_ctrl_prune_entity(dev, entity);
 
 		/* Count supported controls and allocate the controls array */
-		for (i = 0; i < bControlSize; ++i)
-			ncontrols += hweight8(bmControls[i]);
+		ncontrols = memweight(bmControls, bControlSize);
 		if (ncontrols == 0)
 			continue;