missing annotation in fs/file.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/file.c

@@ -750,6 +750,7 @@ bool get_close_on_exec(unsigned int fd)
 
 static int do_dup2(struct files_struct *files,
 	struct file *file, unsigned fd, unsigned flags)
+__releases(&files->file_lock)
 {
 	struct file *tofree;
 	struct fdtable *fdt;