cciss: switch to using hlist for command list management

This both cleans up the code and also helps detect the spurious case
of a command attempted being removed from a queue it doesn't belong
to.

Acked-by: Mike Miller <mike.miller@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --cc drivers/block/cciss.c
Simple merge

diff --cc drivers/block/cciss.h
Simple merge

diff --cc drivers/block/cciss_cmd.h
Simple merge