-Undo presumably accidental removal of helpful error message from packimage done in revision 1175

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@1181 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-server-2.0/lib/xcat/plugins/packimage.pm

@@ -117,6 +117,10 @@ sub process_request {
        } elsif ($arch =~ /ppc/) {
           $flags="-be";
        }
+       if (! -x "/sbin/mksquashfs") {
+          $callback->({error=>["mksquashfs not found, squashfs-tools rpm should be installed on the management node"],errorcode=>[1]});
+          return;
+       }
        my $rc = system("mksquashfs $temppath ../rootimg.sfs $flags");
        if ($rc) {
           $callback->({error=>["mksquashfs could not be run successfully"],errorcode=>[1]});