net: Make sure BHs are disabled in sock_prot_inuse_add()

There is still a call to sock_prot_inuse_add() in af_netlink
while in a preemptable section. Add explicit BH disable around
this call.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netlink/af_netlink.c

@@ -515,7 +515,9 @@ static int netlink_release(struct socket *sock)
 	kfree(nlk->groups);
 	nlk->groups = NULL;
 
+	local_bh_disable();
 	sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
+	local_bh_enable();
 	sock_put(sk);
 	return 0;
 }