usb: gadget: uvc: configfs: Move function to avoid forward declaration

The to_f_uvc_opts() function is forward-declared without needing to, as
its definition can simply be moved up in the file. Fix it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/function/uvc_configfs.c

@@ -31,7 +31,11 @@ static struct configfs_attribute prefix##attr_##cname = { \
 	.show		= prefix##cname##_show,				\
 }
 
-static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item);
+static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
+{
+	return container_of(to_config_group(item), struct f_uvc_opts,
+			    func_inst.group);
+}
 
 /* control/header/<NAME> */
 DECLARE_UVC_HEADER_DESCRIPTOR(1);
@@ -2105,12 +2109,6 @@ static const struct config_item_type uvcg_streaming_grp_type = {
 	.ct_owner = THIS_MODULE,
 };
 
-static inline struct f_uvc_opts *to_f_uvc_opts(struct config_item *item)
-{
-	return container_of(to_config_group(item), struct f_uvc_opts,
-			    func_inst.group);
-}
-
 static void uvc_attr_release(struct config_item *item)
 {
 	struct f_uvc_opts *opts = to_f_uvc_opts(item);