EX-7601 llite: rename compr information in io

EX-7601 llite: rename compr information in io

The compression related information in the cl_io is named
poorly.  It's not that the IO is compressed, it's that the
IO is to a compressed file.  The compr_chunk_log_bits is
the maximum from the entire file, not the maximum hit by
this IO.  (This is used by readahead, so the maximum in the
whole file is what's desired.)

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: I46981a98628f127e7b147280caaf7544fa288786
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51771
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>