usb: gadget: make return of 0 explicit

Delete unnecessary local variable whose value is always 0 and that hides
the fact that the result is always 0.

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

// <smpl>
@r exists@
local idexpression ret;
expression e;
position p;
@@

-ret = 0;
... when != ret = e
return
- ret
+ 0
  ;
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/composite.c

@@ -1312,9 +1312,7 @@ static void fill_ext_compat(struct usb_configuration *c, u8 *buf)
 static int count_ext_prop(struct usb_configuration *c, int interface)
 {
 	struct usb_function *f;
-	int j, res;
-
-	res = 0;
+	int j;
 
 	f = c->interface[interface];
 	for (j = 0; j < f->os_desc_n; ++j) {
@@ -1326,7 +1324,7 @@ static int count_ext_prop(struct usb_configuration *c, int interface)
 		if (d && d->ext_compat_id)
 			return d->ext_prop_count;
 	}
-	return res;
+	return 0;
 }
 
 static int len_ext_prop(struct usb_configuration *c, int interface)

drivers/usb/gadget/dummy_hcd.c

@@ -561,7 +561,6 @@ static int dummy_disable(struct usb_ep *_ep)
 	struct dummy_ep		*ep;
 	struct dummy		*dum;
 	unsigned long		flags;
-	int			retval;
 
 	ep = usb_ep_to_dummy_ep(_ep);
 	if (!_ep || !ep->desc || _ep->name == ep0name)
@@ -571,12 +570,11 @@ static int dummy_disable(struct usb_ep *_ep)
 	spin_lock_irqsave(&dum->lock, flags);
 	ep->desc = NULL;
 	ep->stream_en = 0;
-	retval = 0;
 	nuke(dum, ep);
 	spin_unlock_irqrestore(&dum->lock, flags);
 
 	dev_dbg(udc_dev(dum), "disabled %s\n", _ep->name);
-	return retval;
+	return 0;
 }
 
 static struct usb_request *dummy_alloc_request(struct usb_ep *_ep,