unix: fix tests on NetBSD 8.0

Use /dev/ptyp* instead of /dev/ttyp* which don't seem to be available on
NetBSD 8.0+ anymore.

Change-Id: Idda6cc91b8cd26f5488852027b8d918f35a5e8fb
Reviewed-on: https://go-review.googlesource.com/80615
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

unix/dev_netbsd_test.go

@@ -20,11 +20,11 @@ func TestDevices(t *testing.T) {
 		minor uint32
 	}{
 		// well known major/minor numbers according to /dev/MAKEDEV on
-		// NetBSD 7.0
+		// NetBSD 8.0
 		{"/dev/null", 2, 2},
 		{"/dev/zero", 2, 12},
-		{"/dev/ttyp0", 5, 0},
-		{"/dev/ttyp1", 5, 1},
+		{"/dev/ptyp0", 6, 0},
+		{"/dev/ptyp1", 6, 1},
 		{"/dev/random", 46, 0},
 		{"/dev/urandom", 46, 1},
 	}