usb: gadget: net2272: fix missing unlock on error in net2272_irq()

Add the missing unlock on the error handle path in function
net2272_irq().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/net2272.c

@@ -2069,8 +2069,10 @@ static irqreturn_t net2272_irq(int irq, void *_dev)
 #if defined(PLX_PCI_RDK2)
 	/* see if PCI int for us by checking irqstat */
 	intcsr = readl(dev->rdk2.fpga_base_addr + RDK2_IRQSTAT);
-	if (!intcsr & (1 << NET2272_PCI_IRQ))
+	if (!intcsr & (1 << NET2272_PCI_IRQ)) {
+		spin_unlock(&dev->lock);
 		return IRQ_NONE;
+	}
 	/* check dma interrupts */
 #endif
 	/* Platform/devcice interrupt handler */