net: fix protocol number for IPv6 test

The protocol number of ICMP for IPv6 is 58, not 1.

R=golang-dev, iant, r
CC=golang-dev
https://golang.org/cl/8663048

src/pkg/net/ipraw_test.go

@@ -28,7 +28,7 @@ var resolveIPAddrTests = []resolveIPAddrTest{
 
 	{"ip", "::1", &IPAddr{IP: ParseIP("::1")}, nil},
 	{"ip6", "::1", &IPAddr{IP: ParseIP("::1")}, nil},
-	{"ip6:icmp", "::1", &IPAddr{IP: ParseIP("::1")}, nil},
+	{"ip6:ipv6-icmp", "::1", &IPAddr{IP: ParseIP("::1")}, nil},
 
 	{"ip", "::1%en0", &IPAddr{IP: ParseIP("::1"), Zone: "en0"}, nil},
 	{"ip6", "::1%911", &IPAddr{IP: ParseIP("::1"), Zone: "911"}, nil},