staging: rtl8712u: Remove dummy reset-resume callback

An USB wireless dongle uses rtl8712u stops working after system
suspend/resume.

When a USB device lost its power during suspend, the USB core knows the
power was lost and a reset-resume or a re-probe is required. But rtl8712u
provides a dummy reset-resume callback, which gets called and renders
the device dead after resume.

So remove the reset-resume call back, if power was lost during suspend,
let the USB core unbind and probe the device to solve the issue.
Signed-off-by: NKai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/usb_intf.c

@@ -232,13 +232,6 @@ static int r871x_resume(struct usb_interface *pusb_intf)
 	rtl871x_intf_resume(padapter);
 	return 0;
 }
-
-static int r871x_reset_resume(struct usb_interface *pusb_intf)
-{
-	/* dummy routine */
-	return 0;
-}
-
 #endif
 
 static struct drv_priv drvpriv = {
@@ -249,7 +242,6 @@ static struct drv_priv drvpriv = {
 #ifdef CONFIG_PM
 	.r871xu_drv.suspend = r871x_suspend,
 	.r871xu_drv.resume = r871x_resume,
-	.r871xu_drv.reset_resume = r871x_reset_resume,
 #endif
 };