[PATCH bpf-next] bpf: Fix returned error sign when link doesn't support updates

System calls encode returned errors as negative values. Fix a typo that
breaks this convention for bpf(LINK_UPDATE) when bpf_link doesn't support
update operation.

Fixes: f9d041271cf4 ("bpf: Refactor bpf_link update handling")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
 kernel/bpf/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 431241c74614..f9c86e0579da 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c

@@ -3913,7 +3913,7 @@ static int link_update(union bpf_attr *attr)
 	if (link->ops->update_prog)
 		ret = link->ops->update_prog(link, new_prog, old_prog);
 	else
-		ret = EINVAL;
+		ret = -EINVAL;
 
 out_put_progs:
 	if (old_prog)

-- 
2.25.4