[IPv4] fib: Fix out of bound access of fib_props[]

Fixes a typo which caused fib_props[] to have the wrong size
and makes sure the value used to index the array which is
provided by userspace via netlink is checked to avoid out of
bound access.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 2f1fdae..3dad12e 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -89,7 +89,7 @@
 {
 	int	error;
 	u8	scope;
-} fib_props[RTA_MAX + 1] = {
+} fib_props[RTN_MAX + 1] = {
 	{
 		.error	= 0,
 		.scope	= RT_SCOPE_NOWHERE,