LU-14008 o2iblnd: cleanup

LU-14008 o2iblnd: cleanup

simplify kiblnd_send by avoid code duplication.
lets pickup idle tx first.

Lustre-change: https://review.whamcloud.com/40260
Lustre-commit: 3916b9d7226ebb21cf413dd7685afa693e243513

Test-Parameters: trivial
HPE-bug-id: LUS-1796
Change-Id: Iaf71a9a3aeb3047a086d4cc0a3cf4f1dbe8944b4
Signed-off-by: Alexey Lyashkov <alexey.lyashkov@hpe.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/53765
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>