component/bt: Fix exception when there is no device name

components/bt/bluedroid/api/include/esp_bt_device.h

@@ -27,15 +27,17 @@ extern "C" {
 /**
  *
  * @brief      Get bluetooth device address.  Must use after "esp_bluedroid_enable".
- * 
+ *
  * @return     bluetooth device address (six bytes), or NULL if bluetooth stack is not enabled
  */
 const uint8_t *esp_bt_dev_get_address(void);
 
 
 /**
- * @brief           Set bluetooth device name. This function should be called after esp_bluedroid_enable() 
- *                  completes successfully
+ * @brief           Set bluetooth device name. This function should be called after esp_bluedroid_enable()
+ *                  completes successfully.
+ *                  A BR/EDR/LE device type shall have a single Bluetooth device name which shall be
+ *                  identical irrespective of the physical channel used to perform the name discovery procedure.
  *
  * @param[in]       name : device name to be set
  *