USB: gadget: s3c-hsotg: Add missing unlock

In an error handling case the lock is not unlocked.  The return is
converted to a goto, to share the unlock at the end of the function.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E1;
identifier f;
@@

f (...) { <+...
* spin_lock_irqsave (E1,...);
... when != E1
* return ...;
...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/s3c-hsotg.c

@@ -2145,6 +2145,7 @@ static int s3c_hsotg_ep_enable(struct usb_ep *ep,
 	u32 epctrl;
 	u32 mps;
 	int dir_in;
+	int ret = 0;
 
 	dev_dbg(hsotg->dev,
 		"%s: ep %s: a 0x%02x, attr 0x%02x, mps 0x%04x, intr %d\n",
@@ -2196,7 +2197,8 @@ static int s3c_hsotg_ep_enable(struct usb_ep *ep,
 	switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
 	case USB_ENDPOINT_XFER_ISOC:
 		dev_err(hsotg->dev, "no current ISOC support\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 
 	case USB_ENDPOINT_XFER_BULK:
 		epctrl |= S3C_DxEPCTL_EPType_Bulk;
@@ -2235,8 +2237,9 @@ static int s3c_hsotg_ep_enable(struct usb_ep *ep,
 	/* enable the endpoint interrupt */
 	s3c_hsotg_ctrl_epint(hsotg, index, dir_in, 1);
 
+out:
 	spin_unlock_irqrestore(&hs_ep->lock, flags);
-	return 0;
+	return ret;
 }
 
 static int s3c_hsotg_ep_disable(struct usb_ep *ep)