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: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 042c66b..f801519 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1312,9 +1312,7 @@
 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 @@
 		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)