target-openrisc: Free typename in openrisc_cpu_class_by_name

We should free typename here.

Signed-off-by: Jia Liu <proljc@gmail.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-openrisc/cpu.c b/target-openrisc/cpu.c
index 6d40f1b..e348df0 100644
--- a/target-openrisc/cpu.c
+++ b/target-openrisc/cpu.c
@@ -99,6 +99,7 @@
 
     typename = g_strdup_printf("%s-" TYPE_OPENRISC_CPU, cpu_model);
     oc = object_class_by_name(typename);
+    g_free(typename);
     if (oc != NULL && (!object_class_dynamic_cast(oc, TYPE_OPENRISC_CPU) ||
                        object_class_is_abstract(oc))) {
         return NULL;