ext4: fix underflow in ext4_max_bitmap_size()

hulk inclusion
category: bugfix
bugzilla: 186216, https://gitee.com/openeuler/kernel/issues/I4PW7R


CVE: NA

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The same to commit 1c2d1421 ("ext2: Fix underflow in ext2_max_size()")
in ext2 filesystem, ext4 driver has the same issue with 64K block size
and ^huge_file, fix this issue the same as ext2. This patch also revert
commit 75ca6ad4 ("ext4: fix loff_t overflow in ext4_max_bitmap_size()")
because it's no longer needed.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Conflicts:
	fs/ext4/super.c

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>