Merge branch 'tunnel-mtu-fixes'

Xin Long says:

====================
net: fix IFLA_MTU ignored on NEWLINK for some ip and ipv6 tunnels

The fix for ip_gre follows the way other ip tunnels do: not to
set mtu in ndo_init, as ip_tunnel_newlink will take care of it
properly.

The fix for ip6_tunnel and sit follows the way ipv6 tunenls do:
to set mtu again according to IFLA_MTU after, as all bind_dev
are called in ndo_init where it can't get the tb[IFLA_MTU].
====================

Signed-off-by: David S. Miller <davem@davemloft.net>