[NETNS][IPV6] ip6_fib - gc timer per namespace

Move the timer initialization at the network namespace creation and
store the network namespace in the timer argument.

That enables multiple timers (one per network namespace) to do garbage
collecting.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index a158abe..79dce49 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -78,7 +78,7 @@
 					 struct in6_addr *addr);
 extern int icmp6_dst_gc(int *more);
 
-extern void fib6_force_start_gc(void);
+extern void fib6_force_start_gc(struct net *net);
 
 extern struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
 					   const struct in6_addr *addr,