modbus: fix tcp slave destroy issues

Closes https://github.com/espressif/esp-idf/issues/8211

components/freemodbus/tcp_slave/modbus_controller/mbc_tcp_slave.c

@@ -119,7 +119,7 @@ static esp_err_t mbc_tcp_slave_destroy(void)
     (void)vQueueDelete(mbs_opts->mbs_notification_queue_handle);
     (void)vEventGroupDelete(mbs_opts->mbs_event_group);
     (void)vMBTCPPortClose();
-
+    mbs_interface_ptr = NULL;
     vMBPortSetMode((UCHAR)MB_PORT_INACTIVE);
     return ESP_OK;
 }

components/freemodbus/tcp_slave/port/port_tcp_slave.c

@@ -654,6 +654,7 @@ vMBTCPPortDisable( void )
             xConfig.pxMbClientInfo[i] = NULL;
         }
     }
+    free(xConfig.pxMbClientInfo);
     close(xListenSock);
     xListenSock = -1;
     vMBTCPPortRespQueueDelete(xConfig.xRespQueueHandle);