https_server: Fix example test failure

- Closed the client connection gracefully for the https server
  callback check to pass in test
- Made some functions static in the example

examples/protocols/https_server/simple/example_test.py

@@ -141,11 +141,13 @@ def test_examples_protocol_https_server_simple(env, extra_data):  # type: (tiny_
     resp = conn.getresponse()
     dut1.expect('performing session handshake')
     got_resp = resp.read().decode('utf-8')
-    # Close the connection
     if got_resp != success_response:
         Utility.console_log('Response obtained does not match with correct response')
         raise RuntimeError('Failed to test SSL connection')
 
+    # Close the connection
+    conn.close()
+
     Utility.console_log('Checking user callback: Obtaining client certificate...')
 
     serial_number = dut1.expect(re.compile(r'serial number(.*)'), timeout=5)[0]
@@ -158,7 +160,6 @@ def test_examples_protocol_https_server_simple(env, extra_data):  # type: (tiny_
 
     Utility.console_log('Correct response obtained')
     Utility.console_log('SSL connection test successful\nClosing the connection')
-    conn.close()
 
 
 if __name__ == '__main__':

examples/protocols/https_server/simple/main/main.c

@@ -37,7 +37,7 @@ static esp_err_t root_get_handler(httpd_req_t *req)
 
 #if CONFIG_EXAMPLE_ENABLE_HTTPS_USER_CALLBACK
 
-void print_peer_cert_info(const mbedtls_ssl_context *ssl)
+static void print_peer_cert_info(const mbedtls_ssl_context *ssl)
 {
     const mbedtls_x509_crt *cert;
     const size_t buf_size = 1024;
@@ -72,7 +72,7 @@ void print_peer_cert_info(const mbedtls_ssl_context *ssl)
  * The config option is found here - Component config → ESP-TLS
  *
  */
-void https_server_user_callback(esp_https_server_user_cb_arg_t *user_cb)
+static void https_server_user_callback(esp_https_server_user_cb_arg_t *user_cb)
 {
     ESP_LOGI(TAG, "User callback invoked!");