Use void arguments list consistently in C code

On my way, fixed a couple of cases where we had `()` in the header, and
non-empty argument list in the source file.

PUBLISHED_FROM=5519526cf84e2bbd425a726fcc112fea1a95cbf1

examples/CC3200/ccs/MG_hello/main.c

@@ -186,7 +186,7 @@ static void mg_init(struct mg_mgr *mgr) {
 extern void (*const g_pfnVectors[])(void);
 #endif
 
-int main() {
+int main(void) {
 #ifndef USE_TIRTOS
   MAP_IntVTableBaseSet((unsigned long) &g_pfnVectors[0]);
 #endif
@@ -223,10 +223,10 @@ int main() {
 }
 
 /* These are FreeRTOS hooks for various life situations. */
-void vApplicationMallocFailedHook() {
+void vApplicationMallocFailedHook(void) {
 }
 
-void vApplicationIdleHook() {
+void vApplicationIdleHook(void) {
 }
 
 void vApplicationStackOverflowHook(OsiTaskHandle *th, signed char *tn) {

examples/CC3200/data.c

@@ -47,7 +47,7 @@ void data_init_sensors(int tmp006_addr, int bm222_addr) {
   }
 }
 
-void data_collect() {
+void data_collect(void) {
   double volt = tmp006_read_sensor_voltage(s_tmp006_addr);
   double temp = tmp006_read_die_temp(s_tmp006_addr);
   if (volt != TMP006_INVALID_READING && temp != TMP006_INVALID_READING) {

examples/CC3200/data.h

@@ -8,7 +8,7 @@
 
 #include "mongoose.h"
 
-void data_collect();
+void data_collect(void);
 void data_init_sensors(int tmp006_addr, int bm222_addr);
 void data_conn_handler(struct mg_connection *nc, int ev, void *p);
 

examples/CC3200/main.c

@@ -222,7 +222,7 @@ static void mg_init(struct mg_mgr *mgr) {
 extern void (*const g_pfnVectors[])(void);
 #endif
 
-int main() {
+int main(void) {
 #ifndef USE_TIRTOS
   MAP_IntVTableBaseSet((unsigned long) &g_pfnVectors[0]);
 #endif
@@ -274,10 +274,10 @@ int main() {
 }
 
 /* These are FreeRTOS hooks for various life situations. */
-void vApplicationMallocFailedHook() {
+void vApplicationMallocFailedHook(void) {
 }
 
-void vApplicationIdleHook() {
+void vApplicationIdleHook(void) {
 }
 
 void vApplicationStackOverflowHook(OsiTaskHandle *th, signed char *tn) {

examples/CC3200/wifi.h

@@ -10,6 +10,6 @@
 
 bool wifi_setup_ap(const char *ssid, const char *pass, int channel);
 bool wifi_setup_sta(const char *ssid, const char *pass);
-void stop_nwp();
+void stop_nwp(void);
 
 #endif /* CS_MONGOOSE_EXAMPLES_CC3200_WIFI_H_ */

examples/ESP8266_RTOS/user/user_main.c

@@ -54,7 +54,7 @@ void ev_handler(struct mg_connection *nc, int ev, void *p) {
   }
 }
 
-void setup_ap() {
+void setup_ap(void) {
   int off = 0;
   struct ip_info info;
   struct softap_config cfg;

examples/coap_server/coap_server.c

@@ -42,7 +42,7 @@ static void coap_handler(struct mg_connection *nc, int ev, void *p) {
   }
 }
 
-int main() {
+int main(void) {
   struct mg_mgr mgr;
   struct mg_connection *nc;
 

examples/cookie_auth/cookie_auth.c

@@ -183,7 +183,7 @@ static void logout_handler(struct mg_connection *nc, int ev, void *p) {
 }
 
 /* Cleans up sessions that have been idle for too long. */
-void check_sessions() {
+void check_sessions(void) {
   double threshold = mg_time() - SESSION_TTL;
   for (int i = 0; i < NUM_SESSIONS; i++) {
     struct session *s = &s_sessions[i];

examples/simple_crawler/simple_crawler.c

@@ -40,7 +40,7 @@ static void event_handler(struct mg_connection *nc, int event, void *data) {
   }
 }
 
-int main() {
+int main(void) {
   struct mg_mgr mgr;
 
   mg_mgr_init(&mgr, NULL);