LU-15646 llog: correct llog FID and path output

LU-15646 llog: correct llog FID and path output

- fix wrong LLOG_ID-to-FID convertion to output llog FID by
  introducing PLOGID macro to expand llog ID for DFID format
- stop printing lgl_ogen along with llog FID as it always zero
  since 2.3.51 and is not used anymore
- output correct path for update llog in llog_reader
- always print header info in llog_reader if available
- print llog flags in header info

Fixes: 5a8e47d0a1a7 ("LU-9153 llog: update llog print format to use FIDs")
Signed-off-by: Mikhail Pershin <mpershin@whamcloud.com>
Change-Id: I7ba49e8101a67d2d80c204a5fc629bfd0bce89ad
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/48430
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>