Mounting a non-affs filesystem as affs crashes the kernel.
The reason is the
	sbi = kmalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
	memset(sbi, 0, sizeof(*AFFS_SB));
where the second sizeof is 1, so that sbi is not zeroed at all.

Also, avoid a warning for printk of sector_t in amigaffs.h.