modesetting: Use seq instead of msc in ms_queue_vblank failure path

When the call to queue a vblank event fails, we need to clean up by
removing the user-space queue entry. That is indexed by the local
sequence number, not by the kernel vblank count. The call in this
case was just passing the wrong value.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

hw/xfree86/drivers/modesetting/vblank.c

@@ -229,7 +229,7 @@ ms_queue_vblank(xf86CrtcPtr crtc, ms_queue_flag flags,
             return TRUE;
         }
         if (errno != EBUSY) {
-            ms_drm_abort_seq(scrn, msc);
+            ms_drm_abort_seq(scrn, seq);
             return FALSE;
         }
         ms_flush_drm_events(screen);