When an error happens in the update sockmap element logic also pass
the err up to the user.
Fixes: e5cd3abcb31a ("bpf: sockmap, refactor sockmap routines to work with hashmap") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>