igmp: remove unnecessary in_device member zeroing

ip_mc_init_dev() is passed a freshly kzalloc'd in_device so it is
unnecessary to explicitly zero out the members.
Signed-off-by: NShawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/igmp.c

@@ -1435,13 +1435,9 @@ void ip_mc_init_dev(struct in_device *in_dev)
 {
 	ASSERT_RTNL();
 
-	in_dev->mc_tomb = NULL;
 #ifdef CONFIG_IP_MULTICAST
-	in_dev->mr_gq_running = 0;
 	setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
 			(unsigned long)in_dev);
-	in_dev->mr_ifc_count = 0;
-	in_dev->mc_count     = 0;
 	setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
 			(unsigned long)in_dev);
 	in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;