[NETFILTER]: nfnetlink_log: fix module reference counting

Count module references correctly: after instance_destroy() there
might be timer pending and holding a reference for this netlink instance.

Based on patch by Michal Miroslaw <mirq-linux@rere.qmqm.pl>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index b669db5..d0af8bc 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -133,6 +133,7 @@
 	if (inst && atomic_dec_and_test(&inst->use)) {
 		UDEBUG("kfree(inst=%p)\n", inst);
 		kfree(inst);
+		module_put(THIS_MODULE);
 	}
 }
 
@@ -228,8 +229,6 @@
 
 	/* and finally put the refcount */
 	instance_put(inst);
-
-	module_put(THIS_MODULE);
 }
 
 static inline void