LU-17089 mdd: fix for bi_writers ref counter in case of error

LU-17089 mdd: fix for bi_writers ref counter in case of error

If the mdd_child_ops() called from mdd_trans_create returns error,
we dont call barrier_exit to decrement the bi_writers. Call
barrier_exit in case of error returned from mdd_child_ops().

This patch also added more CDEBUG messages in lustre/target/barrier.c.

Signed-off-by: Jeya ganesh babu J <jeyaga@amazon.com>
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Ia430df404b700167cb9207eb13ac938575a2030a
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/52275
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>