ext4: simplify ext4 error translation

mainline inclusion
from mainline-v5.11-rc1
commit 02a7780e
category: bugfix
bugzilla: 50839
CVE: NA

-----------------------------------------------

We convert errno's to ext4 on-disk format error codes in
save_error_info(). Add a function and a bit of macro magic to make this
simpler.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201127113405.26867-7-jack@suse.cz


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>