fib: Fix fib zone and its hash leak on namespace stop

When we stop a namespace we flush the table and free one, but the
added fn_zone-s (and their hashes if grown) are leaked. Need to free.
Tries releases all its stuff in the flushing code.

Shame on us - this bug exists since the very first make-fib-per-net
patches in 2.6.27 :(

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index ba3666d..07bdb5e 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -158,6 +158,8 @@
 extern void fib_table_select_default(struct fib_table *table,
 				     const struct flowi *flp,
 				     struct fib_result *res);
+extern void fib_free_table(struct fib_table *tb);
+
 
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES