Slight change to disk/part specification. The new netdisk expects to

see something like either wd0 or wd0:s1 or wd0:s1a. This is to keep
the command line parsing simple in the face of allowing multiple loads
at a time on the command line.

tbsetup/os_load.in

@@ -121,7 +121,7 @@ if (! -f $imagepath) {
 #
 my $diskpart = "";
 if ($imagepart) {
-    $diskpart = "wd0 s${imagepart}";
+    $diskpart = "wd0:s${imagepart}";
 }
 else {
     $diskpart = "wd0";