-Fix problem where anaconda always populated a variable even if it isn't to be used

git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@8707 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd

xCAT-server/lib/xcat/plugins/anaconda.pm

@@ -587,7 +587,7 @@ sub mknetboot
         #}
         # append the mac address
         my $mac;
-        if($machash->{$node}->[0] && $machash->{$node}->[0]->{'mac'}) {
+        if($useifname && $machash->{$node}->[0] && $machash->{$node}->[0]->{'mac'}) {
             # TODO: currently, only "mac" attribute with classic style is used, the "|" delimited string of "macaddress!hostname" format is not used
             $mac = $machash->{$node}->[0]->{'mac'};
             if ( (index($mac, "|") eq -1) and (index($mac, "!") eq -1) ) {