[NETNS]: Compilation warnings under CONFIG_NET_NS.

Recent commits from YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
have been introduced a several compilation warnings
'assignment discards qualifiers from pointer target type'
due to extra const modifier in the inline call parameters of
{dev|sock|twsk}_net_set.

Drop it.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -753,7 +753,7 @@ struct net *dev_net(const struct net_device *dev)
 }
 
 static inline
-void dev_net_set(struct net_device *dev, const struct net *net)
+void dev_net_set(struct net_device *dev, struct net *net)
 {
 #ifdef CONFIG_NET_NS
 	dev->nd_net = net;

include/net/inet_timewait_sock.h

@@ -219,7 +219,7 @@ struct net *twsk_net(const struct inet_timewait_sock *twsk)
 }
 
 static inline
-void twsk_net_set(struct inet_timewait_sock *twsk, const struct net *net)
+void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
 {
 #ifdef CONFIG_NET_NS
 	twsk->tw_net = net;

include/net/sock.h

@@ -1358,7 +1358,7 @@ struct net *sock_net(const struct sock *sk)
 }
 
 static inline
-void sock_net_set(struct sock *sk, const struct net *net)
+void sock_net_set(struct sock *sk, struct net *net)
 {
 #ifdef CONFIG_NET_NS
 	sk->sk_net = net;