staging: r8712u: Fix regression caused by commit 8c213fa

In commit 8c213fa "staging: r8712u: Use asynchronous firmware loading",
the command to release the firmware was placed in the wrong routine.

In combination with the bug introduced in commit a5ee652 "staging: r8712u:
Interface-state not fully tracked", the driver attempts to upload firmware
that had already been released. This bug is the source of one of the
problems in https://bugs.archlinux.org/task/27996#comment89833.

Tested-by: Alberto Lago Ballesteros <saniukeokusainaya@gmail.com>
Tested-by: Adrian <agib@gmx.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/rtl8712/usb_intf.c b/drivers/staging/rtl8712/usb_intf.c
index fe0e2ff..e01fe14 100644
--- a/drivers/staging/rtl8712/usb_intf.c
+++ b/drivers/staging/rtl8712/usb_intf.c
@@ -30,6 +30,7 @@
 
 #include <linux/usb.h>
 #include <linux/module.h>
+#include <linux/firmware.h>
 
 #include "osdep_service.h"
 #include "drv_types.h"
@@ -620,6 +621,10 @@
 	struct _adapter *padapter = netdev_priv(pnetdev);
 	struct usb_device *udev = interface_to_usbdev(pusb_intf);
 
+	if (padapter->fw_found)
+		release_firmware(padapter->fw);
+	/* never exit with a firmware callback pending */
+	wait_for_completion(&padapter->rtl8712_fw_ready);
 	usb_set_intfdata(pusb_intf, NULL);
 	if (padapter) {
 		if (drvpriv.drv_registered == true)