fix text_freeFontCache prototype

src/text.c

@@ -13,7 +13,7 @@ typedef struct FontCacheObject {
 FontCacheObject_t fontCache[FONT_CACHE_SIZE];
 unsigned fontCacheSize = 0;
 
-void text_freeFontCache(){
+void text_freeFontCache(void){
     for(unsigned i = 0; i < fontCacheSize; ++i){
         free(fontCache[i].file);
         TTF_CloseFont(fontCache[i].font);