cciss: enqueue and submit io

Clean up some code where we subit our io.  The same 5 lines appeared
several times.  Also helps for a following patch.

Signed-off-by: Mike Miller <mike.miller@hp.com>
Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>