[NETFILTER]: Missing unlock in TCP connection tracking error path

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
index f23ef1f..1985abc 100644
--- a/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
+++ b/net/ipv4/netfilter/ip_conntrack_proto_tcp.c
@@ -349,6 +349,7 @@
 	return 0;
 
 nfattr_failure:
+	read_unlock_bh(&tcp_lock);
 	return -1;
 }
 #endif