qemu: Free priv->machineName

Commit c3bd0019c0 forgot to cleanup after itself.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1325043

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>

src/qemu/qemu_cgroup.c

@@ -1123,5 +1123,7 @@ qemuRemoveCgroup(virDomainObjPtr vm)
             VIR_DEBUG("Failed to terminate cgroup for %s", vm->def->name);
     }
 
+    VIR_FREE(priv->machineName);
+
     return virCgroupRemove(priv->cgroup);
 }