LU-4423 ptlrpc: use list_move where appropriate.

LU-4423 ptlrpc: use list_move where appropriate.

There are several places in lustre where "list_del" (or occasionally
"list_del_init") is followed by "list_add" or "list_add_tail" which
moves the object to a different list.
These can be combined into "list_move" or "list_move_tail".

Change-Id: I9ca0df11cd655b9a63a4889dd4388b3b8c8bc992
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-on: https://review.whamcloud.com/35507
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>