esp_wifi: Modify wifi scan return value.

1. Modify wifi scan return value same to docs.
2. Change some logs' log level wo avoid misunderstanding.
3. Fix connect fail return wrong error code issue

docs/en/api-guides/wifi.rst

@@ -1143,10 +1143,11 @@ The table below shows the Wi-Fi reason-code may related to wrong password.
      - Description
    * - 4WAY_HANDSHAKE_TIMEOUT
      - 15
-     - Four-way handshake times out.
+     - Four-way handshake times out. Setting wrong password when STA connecting to an encrpted AP.
    * - NO_AP_FOUND
      - 201
      - This may related to wrong password in the two scenarios:
+
        - Setting password when STA connecting to an unencrypted AP.
        - Doesn't setting password when STA connecting to an encrpted AP.
    * - HANDSHAKE_TIMEOUT
@@ -1154,6 +1155,23 @@ The table below shows the Wi-Fi reason-code may related to wrong password.
      - Four-way handshake fails.
 
 
+The table below shows the Wi-Fi reason-code may related to low RSSI.
+
+.. list-table::
+   :header-rows: 1
+   :widths: 5 10 40
+
+   * - Reason code
+     - Value
+     - Description
+   * - NO_AP_FOUND
+     - 201
+     - The station fails to scan the target AP due to low RSSI
+   * - HANDSHAKE_TIMEOUT
+     - 204
+     - Four-way handshake fails.
+
+
 {IDF_TARGET_NAME} Wi-Fi Station Connecting When Multiple APs Are Found
 ----------------------------------------------------------------------
 

docs/zh_CN/api-guides/wifi.rst

@@ -1113,10 +1113,11 @@ Wi-Fi 原因代码
      - 描述
    * - 4WAY_HANDSHAKE_TIMEOUT
      - 15
-     - 四次握手超时。
+     - 四次握手超时。STA 在连接加密的 AP 的时候输入了错误的密码
    * - NO_AP_FOUND
      - 201
      - 密码错误会出现这个原因代码的场景有如下两个：
+
        - STA 在连接加密的 AP 的时候没有输入密码
        - STA 在连接非加密的 AP 的时候输入了密码
    * - HANDSHAKE_TIMEOUT
@@ -1124,6 +1125,23 @@ Wi-Fi 原因代码
      - 握手超时。
 
 
+下表罗列了与低 RSSI 相关的 Wi-Fi 原因代码。
+
+.. list-table::
+   :header-rows: 1
+   :widths: 5 10 40
+
+   * - 原因代码
+     - 数值
+     - 描述
+   * - NO_AP_FOUND
+     - 201
+     - 低 RSSI 导致 station 无法扫描到目标 AP
+   * - HANDSHAKE_TIMEOUT
+     - 204
+     - 握手超时。
+
+
 找到多个 AP 时的 {IDF_TARGET_NAME} Wi-Fi station 连接
 ----------------------------------------------------------------------