Fix a memory leak in xer_equivalent

Free the internal buffers
diff --git a/skeletons/xer_encoder.c b/skeletons/xer_encoder.c
index 36d8ec2..a655ae3 100644
--- a/skeletons/xer_encoder.c
+++ b/skeletons/xer_encoder.c
@@ -230,6 +230,8 @@
         return XEQ_ROUND_TRIP_FAILED;
     }
 
-    return XEQ_SUCCESS;
+	FREEMEM(xb1.buffer);
+	FREEMEM(xb2.buffer);
+	return XEQ_SUCCESS;
 }