staging: wilc1000: flush the workqueue before deinit the host

Before deinitializing the host interface, the workqueue should be flushed
to handle any pending deferred work
Signed-off-by: Adham Abozaeid <adham.abozaeid@microchip.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190722213837.21952-1-adham.abozaeid@microchip.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/wilc_wfi_cfgoperations.c

@@ -1969,6 +1969,7 @@ void wilc_deinit_host_int(struct net_device *net)
 
 	priv->p2p_listen_state = false;
 
+	flush_workqueue(vif->wilc->hif_workqueue);
 	mutex_destroy(&priv->scan_req_lock);
 	ret = wilc_deinit(vif);