Fix off-by-one in print of wrandom algo.

From: Norbert Buchmuller <norbi@nix.hu>

The 'wrandom' multipath algo is recognised when adding the route, but
not resolved when it is printed (prints 'unknown'):

ianus:~# ip ro add 1.2.3.4 mpath wrandom nexthop dev ppp0 weight 1 nexthop dev ppp1 weight 2
ianus:~# ip ro get to 1.2.3.4
1.2.3.4 mpath unknown dev ppp0  src 62.77.192.67 
    cache  mtu 1492 advmss 1452 hoplimit 64
ianus:~# ip ro del 1.2.3.4 mpath wrandom nexthop dev ppp0 weight 1 nexthop dev ppp1 weight 2

See Debian bug #428440 - http://bugs.debian.org/428440

diff -Naur iproute-20061002/ip/iproute.c iproute-20061002.fixed/ip/iproute.c
--- iproute-20061002/ip/iproute.c	2007-06-11 19:26:52.000000000 +0200
+++ iproute-20061002.fixed/ip/iproute.c	2007-06-11 19:27:29.000000000 +0200
@@ -358,7 +358,7 @@
 		__u32 mp_alg = *(__u32*) RTA_DATA(tb[RTA_MP_ALGO]);
 		if (mp_alg > IP_MP_ALG_NONE) {
 			fprintf(fp, "mpath %s ",
-			    mp_alg < IP_MP_ALG_MAX ? mp_alg_names[mp_alg] : "unknown");
+			    mp_alg <= IP_MP_ALG_MAX ? mp_alg_names[mp_alg] : "unknown");
 		}
 	}