feature: heap command prints the status of the allocator

kprintf: change KERN_DEFAULT to 0

src/kernel.c

@@ -35,7 +35,6 @@ void kernel_main(void)
 	char *str = kalloc(10);
 	kfree(str);
 	str = kalloc(10);
-	show_alloc_mem();
 	strcpy(str, "Hello world\n");
 	kprintf("%s", str);
 	shell_init();