sna: Update the list of outputs after a failed modeset

In case we have a hotplug at just the wrong time, we can fail a modeset
with a stale connector. Before attempting to recover, probe the kernel
for the current state.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

src/sna/sna_display.c

@@ -2173,6 +2173,7 @@ error:
 	sna_crtc->offset = saved_offset;
 	sna_crtc->transform = saved_transform;
 	sna_crtc->bo = saved_bo;
+	sna_mode_discover(sna);
 	return FALSE;
 }