EX-6511 csdc: prefer uncompressed mirror for read

EX-6511 csdc: prefer uncompressed mirror for read

When accessing a mirrored file with both compressed and uncompressed
components, choose uncompressed components for read.

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I043b27bd891c039901075a08c76630f8f0f9f182
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/50791
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>