[PATCH] io_uring: Fix an unsigned subtraction which can never be negative.

[Jiapeng Chong]

Eliminate the follow smatch warnings:

fs/io_uring.c:10358 __do_sys_io_uring_enter() warn: unsigned 'fd' is
never less than zero.

Reported-by: Abaci Robot <abaci@xxxxxxxxxxxxxxxxx>
Signed-off-by: Jiapeng Chong <jiapeng.chong@xxxxxxxxxxxxxxxxx>
---
 fs/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 23e7f93d3956..d970c94804db 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -10355,7 +10355,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
 		if (!tctx)
 			return -EINVAL;
 		if (fd != tctx->last_reg_fd) {
-			if (fd < 0 || fd >= IO_RINGFD_REG_MAX || !tctx)
+			if (fd >= IO_RINGFD_REG_MAX || !tctx)
 				return -EINVAL;
 			tctx->last_reg_fd = array_index_nospec(fd,
 							IO_RINGFD_REG_MAX);
-- 
2.20.1.7.g153144c