usb: gadget: FunctionFS: clear FFS_FL_BOUND flag on unbind (bugfix)

clear FFS_FL_BOUND flag on unbind (bugfix)
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_fs.c

@@ -1382,6 +1382,7 @@ static void functionfs_unbind(struct ffs_data *ffs)
 		ffs->ep0req = NULL;
 		ffs->gadget = NULL;
 		ffs_data_put(ffs);
+		clear_bit(FFS_FL_BOUND, &ffs->flags);
 	}
 }