[C] Fixed some compiler warnings

tests/test_memory_errors.c

@@ -23,7 +23,7 @@ void test_free(void *ptr)
     }
 }
 
-static int create_simple_table_and_show()
+static int create_simple_table_and_show(void)
 {
     FTABLE *table = NULL;
     int result = 0;