LU-12137 osd-ldiskfs: migrate osd_ios_lookup_one_len() to osd_compat.c

LU-12137 osd-ldiskfs: migrate osd_ios_lookup_one_len() to osd_compat.c

The function osd_ios_lookup_one_len() was created for the LFSCK code
to look for a dentry by name and if the inode of that dentry was
NULL treat it as an -ENOENT so LFSCK would repair the file. This
function will be used for more the scrub infrastructure in future
patches so move it to osd_compat.c.

Test-Parameters: trivial

Change-Id: Ic34c1110f8ced7a4a2f7c0fa3b8a9403be9940ca
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/35453
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Neil Brown <neilb@suse.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>