drm/vkms: Dont flush crc worker when we change crc status

The crc core code can cope with some late crc, the race is kinda
unavoidable. So no need to flush pending workers, they'll complete in
time.

Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Tested-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190606222751.32567-8-daniel.vetter@ffwll.ch

drivers/gpu/drm/vkms/vkms_crc.c

@@ -258,9 +258,6 @@ int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name)
 
 	ret = vkms_crc_parse_source(src_name, &enabled);
 
-	/* make sure nothing is scheduled on crtc workq */
-	flush_workqueue(out->crc_workq);
-
 	spin_lock_irq(&out->lock);
 	out->crc_enabled = enabled;
 	spin_unlock_irq(&out->lock);