Make sure all command line arguments get passed to UML

If umlBuildCommandLineChr fails (e.g. due to an unsupported chardev
type), it returns NULL. umlBuildCommandLine does not check for this and
sets this as an argument on the comand line, effectively ending the
argument list. This patch checks for this case and sets the chardev to
"none".
Signed-off-by: NSoren Hansen <soren@linux2go.dk>

src/uml/uml_conf.c

@@ -513,10 +513,10 @@ int umlBuildCommandLine(virConnectPtr conn,
     }
 
     for (i = 0 ; i < UML_MAX_CHAR_DEVICE ; i++) {
-        char *ret;
+        char *ret = NULL;
         if (i == 0 && vm->def->console)
             ret = umlBuildCommandLineChr(vm->def->console, "con");
-        else
+        if (!ret)
             if (virAsprintf(&ret, "con%d=none", i) < 0)
                 goto no_memory;
         ADD_ARG(ret);
@@ -524,13 +524,13 @@ int umlBuildCommandLine(virConnectPtr conn,
 
     for (i = 0 ; i < UML_MAX_CHAR_DEVICE ; i++) {
         virDomainChrDefPtr chr = NULL;
-        char *ret;
+        char *ret = NULL;
         for (j = 0 ; j < vm->def->nserials ; j++)
             if (vm->def->serials[j]->target.port == i)
                 chr = vm->def->serials[j];
         if (chr)
             ret = umlBuildCommandLineChr(chr, "ssl");
-        else
+        if (!ret)
             if (virAsprintf(&ret, "ssl%d=none", i) < 0)
                 goto no_memory;
         ADD_ARG(ret);