io_uring: Fix unsigned 'res' comparison with zero in io_fixup_rw_res()

Smatch warning: io_fixup_rw_res() warn:
	unsigned 'res' is never less than zero.

Change type of 'res' from unsigned to long.

Fixes: d6b7efc ("io_uring/rw: fix error'ed retry return values")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

io_uring/io_uring.c

@@ -2701,7 +2701,7 @@ static bool __io_complete_rw_common(struct io_kiocb *req, long res)
 	return false;
 }
 
-static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res)
+static inline int io_fixup_rw_res(struct io_kiocb *req, long res)
 {
 	struct io_async_rw *io = req->async_data;