ipv4: fix definition of FIB_TABLE_HASHSZ

a long time ago by the commit

  commit 93456b6d7753def8760b423ac6b986eb9d5a4a95
  Author: Denis V. Lunev <den@openvz.org>
  Date:   Thu Jan 10 03:23:38 2008 -0800

    [IPV4]: Unify access to the routing tables.

the defenition of FIB_HASH_TABLE size has obtained wrong dependency:
it should depend upon CONFIG_IP_MULTIPLE_TABLES (as was in the original
code) but it was depended from CONFIG_IP_ROUTE_MULTIPATH

This patch returns the situation to the original state.

The problem was spotted by Tingwei Liu.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Tingwei Liu <tingw.liu@gmail.com>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_fib.h

@@ -152,18 +152,16 @@ struct fib_result_nl {
 };
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
-
 #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
-
-#define FIB_TABLE_HASHSZ 2
-
 #else /* CONFIG_IP_ROUTE_MULTIPATH */
-
 #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
+#endif /* CONFIG_IP_ROUTE_MULTIPATH */
 
+#ifdef CONFIG_IP_MULTIPLE_TABLES
 #define FIB_TABLE_HASHSZ 256
-
-#endif /* CONFIG_IP_ROUTE_MULTIPATH */
+#else
+#define FIB_TABLE_HASHSZ 2
+#endif
 
 extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);