net: fix __ip_mc_inc_group usage

in ip_mc_inc_group, memory allocation flag, not mcast mode, is expected
by __ip_mc_inc_group

similar issue in __ip_mc_join_group, both mcase mode and gfp_t are needed
here, so use ____ip_mc_inc_group(...)

Fixes: 9fb20801 ("net: Fix ip_mc_{dec,inc}_group allocation context")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/igmp.c

@@ -1475,7 +1475,7 @@ EXPORT_SYMBOL(__ip_mc_inc_group);
 
 void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
 {
-	__ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE);
+	__ip_mc_inc_group(in_dev, addr, GFP_KERNEL);
 }
 EXPORT_SYMBOL(ip_mc_inc_group);
 
@@ -2197,7 +2197,7 @@ static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
 	iml->sflist = NULL;
 	iml->sfmode = mode;
 	rcu_assign_pointer(inet->mc_list, iml);
-	__ip_mc_inc_group(in_dev, addr, mode);
+	____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL);
 	err = 0;
 done:
 	return err;