ipvs: fix crash in ip_vs_control_net_cleanup on unload

ipvs: fix crash in ip_vs_control_net_cleanup on unload

	commit 70bf31aa7c3419e793c8c754dbcd06b44b85a07d (2.6.39)
("Add __ip_vs_control_{init,cleanup}_sysctl()")
introduced regression due to wrong __net_init for
__ip_vs_control_cleanup_sysctl. This leads to crash when
the ip_vs module is unloaded.

	Fix it by changing __net_init to __net_exit for
the function that is already renamed to ip_vs_control_net_cleanup_sysctl.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>