uml: correct command line networking parameters

I have been finding that some UML command line networking parameters are
being generated incorrectly.

For more information, see
https://bugzilla.redhat.com/show_bug.cgi?id=706295 .

AUTHORS

@@ -172,6 +172,7 @@ Patches have also been contributed by:
   Supriya Kannery      <supriyak@in.ibm.com>
   Dirk Herrendoerfer   <d.herrendoerfer@herrendoerfer.name>
   Taisuke Yamada       <tai@rakugaki.org>
+  Heath Petersen       <HeathPetersen@Kandre.com>
 
   [....send patches to get your name here....]
 

src/uml/uml_conf.c

@@ -207,7 +207,10 @@ umlBuildCommandLineNet(virConnectPtr conn,
 
     case VIR_DOMAIN_NET_TYPE_ETHERNET:
         /* ethNNN=tuntap,tapname,macaddr,gateway */
-        virBufferAddLit(&buf, "tuntap");
+        virBufferAddLit(&buf, "tuntap,");
+        if (def->ifname) {
+            virBufferAdd(&buf, def->ifname, -1);
+        }
         if (def->data.ethernet.ipaddr) {
             umlReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                            _("IP address not supported for ethernet inteface"));