drm/amd/display: do not dereference on NULL

WARN_ON() will not kill the process so the second WARN_ON()
will try to dereference NULL pointer.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -9013,7 +9013,10 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		}
 
 		status = dc_stream_get_status(dm_new_crtc_state->stream);
-		WARN_ON(!status);
+
+		if (WARN_ON(!status))
+			continue;
+
 		WARN_ON(!status->plane_count);
 
 		/*