component/bt: Change the queue_data->p_attr->p_value->attr_val.attr_len += queue_data->len code to the if case.

components/bt/bluedroid/stack/gatt/gatt_sr.c

@@ -421,9 +421,9 @@ void gatt_process_exec_write_req (tGATT_TCB *p_tcb, UINT8 op_code, UINT16 len, U
         if (is_prepare_write_valid){
             if((queue_data->p_attr->p_value != NULL) && (queue_data->p_attr->p_value->attr_val.attr_val != NULL)){
                 memcpy(queue_data->p_attr->p_value->attr_val.attr_val+queue_data->offset, queue_data->value, queue_data->len);
+                //don't forget to increase the attribute value length in the gatts database.
+                queue_data->p_attr->p_value->attr_val.attr_len += queue_data->len;
             }
-            //don't forget to increase the attribute value length in the gatts database.
-            queue_data->p_attr->p_value->attr_val.attr_len += queue_data->len;
         }
         osi_free(queue_data);
     }