sock_map and ULP only work together when ULP is loaded after the sock
map is loaded. In the sock_map case we added a check for this to fail
the load if ULP is already set. However, we missed the check on the
sock_hash side.

Add a ULP check to the sock_hash update path.

Fixes: 604326b4 ("bpf, sockmap: convert to generic sk_msg interface")
Reported-by: syzbot+7a6ee4d0078eac6bf782@syzkaller.appspotmail.com
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>