[media] v4l: of: Instead of zeroing bus_type and bus field separately, unify this

Zero the entire struct starting from bus_type. As more fields are added, no
changes will be needed in the function to reset their value explicitly.
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/v4l2-core/v4l2-of.c

@@ -149,8 +149,9 @@ int v4l2_of_parse_endpoint(const struct device_node *node,
 	int rval;
 
 	of_graph_parse_endpoint(node, &endpoint->base);
-	endpoint->bus_type = 0;
-	memset(&endpoint->bus, 0, sizeof(endpoint->bus));
+	/* Zero fields from bus_type to until the end */
+	memset(&endpoint->bus_type, 0, sizeof(*endpoint) -
+	       offsetof(typeof(*endpoint), bus_type));
 
 	rval = v4l2_of_parse_csi_bus(node, endpoint);
 	if (rval)

include/media/v4l2-of.h

@@ -60,6 +60,7 @@ struct v4l2_of_bus_parallel {
  */
 struct v4l2_of_endpoint {
 	struct of_endpoint base;
+	/* Fields below this line will be zeroed by v4l2_of_parse_endpoint() */
 	enum v4l2_mbus_type bus_type;
 	union {
 		struct v4l2_of_bus_parallel parallel;