drm/atomic: Switch to drm_atomic_get_new_crtc_state()

The drm_atomic_connector_check() function uses the deprecated
drm_atomic_get_existing_crtc_state() helper.

This hook is called as part of the global atomic_check, thus before the
states are swapped. The existing state thus points to the new state, and
we can use drm_atomic_get_new_crtc_state() instead.

Reviewed-by: Dmitry Baryshkov <[e-mail]>
Reviewed-by: Ville Syrjälä <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Maxime Ripard <[e-mail]>

drivers/gpu/drm/drm_atomic.c

···
 	}
 
 	if (state->crtc)
-		crtc_state = drm_atomic_get_existing_crtc_state(state->state,
-								state->crtc);
+		crtc_state = drm_atomic_get_new_crtc_state(state->state,
+							   state->crtc);
 
 	if (writeback_job->fb && !crtc_state->active) {
 		drm_dbg_atomic(connector->dev,