usb: dwc3: debugfs: hold the lock in during mode change

The read and write operation is atomic and we need no locking around
this operations. What we need however is a lock that is held which
ensures that the content of the DWC3_GCTL has not been changed. With
this, the conten may have been change changed after the first but before
our write back.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/debugfs.c

@@ -451,7 +451,6 @@ static ssize_t dwc3_mode_write(struct file *file,
 
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
-	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
 
@@ -464,7 +463,6 @@ static ssize_t dwc3_mode_write(struct file *file,
 	if (!strncmp(buf, "otg", 3))
 		reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_OTG);
 
-	spin_lock_irqsave(&dwc->lock, flags);
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
 	spin_unlock_irqrestore(&dwc->lock, flags);