fix(examples): Fix MQTT example print format warnings

Partially addresses #79

Author: david-cermak

examples/mqtt/main/CMakeLists.txt

@@ -1,4 +1,2 @@
 idf_component_register(SRCS "app_main.cpp"
                     INCLUDE_DIRS ".")
-
-target_compile_options(${COMPONENT_LIB} PRIVATE "-Wno-format")

examples/mqtt/main/app_main.cpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
@@ -40,8 +40,8 @@ static void log_error_if_nonzero(const char *message, int error_code)
  */
 static void mqtt_event_handler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data)
 {
-    ESP_LOGD(TAG, "Event dispatched from event loop base=%s, event_id=%d", base, event_id);
-    esp_mqtt_event_handle_t event = (esp_mqtt_event_handle_t)event_data;
+    ESP_LOGD(TAG, "Event dispatched from event loop base=%s, event_id=%" PRIi32 "", base, event_id);
+    auto event = (esp_mqtt_event_handle_t)event_data;
     esp_mqtt_client_handle_t client = event->client;
     int msg_id;
     switch ((esp_mqtt_event_id_t)event_id) {
@@ -95,7 +95,7 @@ static void mqtt_event_handler(void *handler_args, esp_event_base_t base, int32_
     }
 }
 
-static void mqtt_app_start(void)
+static void mqtt_app_start()
 {
     esp_mqtt_client_config_t mqtt_cfg = {};
     mqtt_cfg.broker.address.uri = CONFIG_BROKER_URL;
@@ -111,7 +111,7 @@ static void mqtt_app_start(void)
 extern "C" void app_main(void)
 {
     ESP_LOGI(TAG, "[APP] Startup..");
-    ESP_LOGI(TAG, "[APP] Free memory: %d bytes", esp_get_free_heap_size());
+    ESP_LOGI(TAG, "[APP] Free memory: %" PRIu32 " bytes", esp_get_free_heap_size());
     ESP_LOGI(TAG, "[APP] IDF version: %s", esp_get_idf_version());
 
     esp_log_level_set("*", ESP_LOG_INFO);