usb: gadget: ffs: call functionfs_unbind() if _ffs_func_bind() fails

Function ffs_do_functionfs_bind() calls functionfs_bind() which allocates
usb request and increments refcounts. These things needs to be cleaned
up by if further steps of initialization fail by calling functionfs_unbind().
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/f_fs.c

@@ -2897,11 +2897,17 @@ static int ffs_func_bind(struct usb_configuration *c,
 			 struct usb_function *f)
 {
 	struct f_fs_opts *ffs_opts = ffs_do_functionfs_bind(f, c);
+	struct ffs_function *func = ffs_func_from_usb(f);
+	int ret;
 
 	if (IS_ERR(ffs_opts))
 		return PTR_ERR(ffs_opts);
 
-	return _ffs_func_bind(c, f);
+	ret = _ffs_func_bind(c, f);
+	if (ret && !--ffs_opts->refcnt)
+		functionfs_unbind(func->ffs);
+
+	return ret;
 }