staging: vt6655: Remove vif check from vnt_interrupt

A check for vif is made in vnt_interrupt_work.

There is a small chance of leaving interrupt disabled while vif
is NULL and the work hasn't been scheduled.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
CC: stable@vger.kernel.org # v4.2+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6655/device_main.c

@@ -1137,8 +1137,7 @@ static irqreturn_t vnt_interrupt(int irq,  void *arg)
 {
 	struct vnt_private *priv = arg;
 
-	if (priv->vif)
-		schedule_work(&priv->interrupt_work);
+	schedule_work(&priv->interrupt_work);
 
 	MACvIntDisable(priv->PortOffset);