drm/vc4: fix itnull.cocci warnings

Connector cannot be null because it is a list entry, ie accessed at an
offset from the positions of the list structure pointers themselves.

Generated by: scripts/coccinelle/iterators/itnull.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NEric Anholt <eric@anholt.net>

drivers/gpu/drm/vc4/vc4_crtc.c

@@ -168,7 +168,7 @@ static int vc4_get_clock_select(struct drm_crtc *crtc)
 	struct drm_connector *connector;
 
 	drm_for_each_connector(connector, crtc->dev) {
-		if (connector && connector->state->crtc == crtc) {
+		if (connector->state->crtc == crtc) {
 			struct drm_encoder *encoder = connector->encoder;
 			struct vc4_encoder *vc4_encoder =
 				to_vc4_encoder(encoder);