ipvs: avoid netns exit crash on ip_vs_conn_drop_conntrack

commit 2627b7e1 upstream.

commit 8f4e0a18 ("IPVS netns exit causes crash in conntrack")
added second ip_vs_conn_drop_conntrack call instead of just adding
the needed check. As result, the first call still can cause
crash on netns exit. Remove it.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

net/netfilter/ipvs/ip_vs_conn.c

@@ -777,7 +777,6 @@ static void ip_vs_conn_expire(unsigned long data)
 			ip_vs_control_del(cp);
 
 		if (cp->flags & IP_VS_CONN_F_NFCT) {
-			ip_vs_conn_drop_conntrack(cp);
 			/* Do not access conntracks during subsys cleanup
 			 * because nf_conntrack_find_get can not be used after
 			 * conntrack cleanup for the net.