LU-13211 ldiskfs: rework data-in-dirent for linux 5.4.7+

LU-13211 ldiskfs: rework data-in-dirent for linux 5.4.7+

Linux commit v5.4-rc3-92-g109ba779d6cc
ext4: check for directory entries too close to block end

This impacts the ext4-data-in-dirent.patch due to the usage
of EXT4_DIR_REC_LEN

Invert the original patch from:
  EXT4_DIR_REC_LEN(<int>)        => __EXT4_DIR_REC_LEN(<int>)
  EXT4_DIR_REC_LEN(de->name_len) => EXT4_DIR_REC_LEN(de)
to:
  EXT4_DIR_REC_LEN(<int>)        => EXT4_DIR_REC_LEN(<int>)
  EXT4_DIR_REC_LEN(de->name_len) => EXT4_DIR_ENTRY_LEN(de)

Doing this allows the patch to apply cleanly over a wider
range of kernel releases.

Test-Parameters: trivial
Cray-bug-id: LUS-8478
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: I95349743f323bb150854ff4541bd2c88f01662a6
Reviewed-on: https://review.whamcloud.com/37467
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>