LU-18435 lod: recover layout generation from replay

LU-18435 lod: recover layout generation from replay

The offset of the layout generation is different between struct
lov_mds_md_v1/v3.lmm_layout_gen and lov_comp_md.lcm_layout_gen.
When checking/setting layout gen, we must use layout-specific field.

Otherwise layout generation can be set to 0 (or other random value)
after replay and client can't apply new layout during later update.

Fixes: 13557aa86904 ("LU-15300 mdt: refresh LOVEA with LL granted")
Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I5e4a63cd097d157317e0e8d1a0fca4a46817d118
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56950
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Qian Yingjin <qian@ddn.com>
Reviewed-by: Alexey Lyashkov <alexey.lyashkov@hpe.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>