drm/bridge: Avoid uninitialized variable warning

This code works, but technically it uses "num_in_bus_fmts" before it
has been initialized so it leads to static checker warnings and probably
KMEMsan warnings at run time.  Initialize the variable to zero to
silence the warning.

Fixes: f32df58a ("drm/bridge: Add the necessary bits to support bus format negotiation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/YrrIs3hoGcPVmXc5@kili

drivers/gpu/drm/drm_bridge.c

@@ -847,8 +847,8 @@ static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
 				    struct drm_connector_state *conn_state,
 				    u32 out_bus_fmt)
 {
+	unsigned int i, num_in_bus_fmts = 0;
 	struct drm_bridge_state *cur_state;
-	unsigned int num_in_bus_fmts, i;
 	struct drm_bridge *prev_bridge;
 	u32 *in_bus_fmts;
 	int ret;
@@ -969,7 +969,7 @@ drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge,
 	struct drm_connector *conn = conn_state->connector;
 	struct drm_encoder *encoder = bridge->encoder;
 	struct drm_bridge_state *last_bridge_state;
-	unsigned int i, num_out_bus_fmts;
+	unsigned int i, num_out_bus_fmts = 0;
 	struct drm_bridge *last_bridge;
 	u32 *out_bus_fmts;
 	int ret = 0;