staging: r8188eu: Add _enter_critical_mutex() error handling

_enter_critical_mutex() is a simple call to mutex_lock_interruptible(),
but there is no error handling code for it.

The patch removes wrapper _enter_critical_mutex() and
adds error handling for mutex_lock_interruptible().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/core/rtw_mlme_ext.c

@@ -271,7 +271,8 @@ static s32 dump_mgntframe_and_wait_ack(struct adapter *padapter,
 	if (padapter->bSurpriseRemoved || padapter->bDriverStopped)
 		return -1;
 
-	_enter_critical_mutex(&pxmitpriv->ack_tx_mutex, NULL);
+	if (mutex_lock_interruptible(&pxmitpriv->ack_tx_mutex))
+		return _FAIL;
 	pxmitpriv->ack_tx = true;
 
 	pmgntframe->ack_report = 1;

drivers/staging/rtl8188eu/include/osdep_service.h

@@ -67,15 +67,6 @@ static inline struct list_head *get_list_head(struct __queue *queue)
 	return &(queue->queue);
 }
 
-static inline int _enter_critical_mutex(struct mutex *pmutex,
-					unsigned long *pirqL)
-{
-	int ret;
-
-	ret = mutex_lock_interruptible(pmutex);
-	return ret;
-}
-
 static inline int rtw_netif_queue_stopped(struct net_device *pnetdev)
 {
 	return  netif_tx_queue_stopped(netdev_get_tx_queue(pnetdev, 0)) &&

drivers/staging/rtl8188eu/os_dep/os_intfs.c

@@ -1058,7 +1058,8 @@ static int netdev_open(struct net_device *pnetdev)
 	int ret;
 	struct adapter *padapter = (struct adapter *)rtw_netdev_priv(pnetdev);
 
-	_enter_critical_mutex(&padapter->hw_init_mutex, NULL);
+	if (mutex_lock_interruptible(&padapter->hw_init_mutex))
+		return -ERESTARTSYS;
 	ret = _netdev_open(pnetdev);
 	mutex_unlock(&padapter->hw_init_mutex);
 	return ret;

drivers/staging/rtl8188eu/os_dep/usb_ops_linux.c

@@ -249,7 +249,10 @@ static int usbctrl_vendorreq(struct adapter *adapt, u8 request, u16 value, u16 i
 		goto exit;
 	}
 
-	_enter_critical_mutex(&dvobjpriv->usb_vendor_req_mutex, NULL);
+	if (mutex_lock_interruptible(&dvobjpriv->usb_vendor_req_mutex)) {
+		status = -ERESTARTSYS;
+		goto exit;
+	}
 
 	/*  Acquire IO memory for vendorreq */
 	pIo_buf = dvobjpriv->usb_vendor_req_buf;