staging: erofs: introduce EFSCORRUPTED and more logs

staging: erofs: introduce EFSCORRUPTED and more logs

Previously, EROFS uses EIO to indicate that filesystem
is corrupted as well. However, as Pavel said [1], other
filesystems tend to use EUCLEAN(EFSCORRUPTED) instead,
let's follow what others do right now.

Also, add some more prints to the syslog.

[1] https://lore.kernel.org/lkml/20190813114821.GB11559@amd/

Suggested-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190814103705.60698-1-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>