Add missing voids for empty parameter list

app/src/adb/adb.c

@@ -70,7 +70,7 @@ argv_to_string(const char *const *argv, char *buf, size_t bufsize) {
 }
 
 static void
-show_adb_installation_msg() {
+show_adb_installation_msg(void) {
 #ifndef __WINDOWS__
     static const struct {
         const char *binary;

app/src/icon.c

@@ -271,7 +271,7 @@ error:
 }
 
 SDL_Surface *
-scrcpy_icon_load() {
+scrcpy_icon_load(void) {
     char *icon_path = get_icon_path();
     if (!icon_path) {
         return NULL;

app/src/scrcpy.c

@@ -297,7 +297,7 @@ sc_timeout_on_timeout(struct sc_timeout *timeout, void *userdata) {
 
 // Generate a scrcpy id to differentiate multiple running scrcpy instances
 static uint32_t
-scrcpy_generate_scid() {
+scrcpy_generate_scid(void) {
     struct sc_rand rand;
     sc_rand_init(&rand);
     // Only use 31 bits to avoid issues with signed values on the Java-side