LE: Add error status to failed write operation

Bug: 18833375
Change-Id: Ib91c8e92658a276d813954264897b02863f1148b
diff --git a/stack/gatt/gatt_cl.c b/stack/gatt/gatt_cl.c
index 0dd3c49..0578086 100644
--- a/stack/gatt/gatt_cl.c
+++ b/stack/gatt/gatt_cl.c
@@ -280,7 +280,7 @@
     {
         if (rt != GATT_SUCCESS)
         {
-            GATT_TRACE_ERROR("gatt_act_write() failed op_code=0x%x", op_code);
+            GATT_TRACE_ERROR("gatt_act_write() failed op_code=0x%x rt=%d", op_code, rt);
         }
         gatt_end_operation(p_clcb, rt, NULL);
     }