qemu: Free priv->machineName

Commit c3bd0019 forgot to cleanup after itself.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1325043Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>
(cherry picked from commit 16b41728)

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);
 }