ipv6 mcast: use in6_dev_put in timer handlers instead of __in6_dev_put
ipv6 mcast: use in6_dev_put in timer handlers instead of __in6_dev_put

[ Upstream commit 9260d3e1013701aa814d10c8fc6a9f92bd17d643 ]

It is possible for the timer handlers to run after the call to
ipv6_mc_down so use in6_dev_put instead of __in6_dev_put in the
handler function in order to do proper cleanup when the refcnt
reaches 0. Otherwise, the refcnt can reach zero without the
inet6_dev being destroyed and we end up leaking a reference to
the net_device and see messages like the following,

unregister_netdevice: waiting for eth0 to become free. Usage count = 1

Tested on linux-3.4.43.

Signed-off-by: Salam Noureddine <14d357f7a1dac3c941d9af90017a1e294ac06a28@aristanetworks.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas