cciss: move next_command function from ifdef

The definition of next_command also ended up in wrong place It ended up
inside an "#ifdef CONFIG_PROCFS".  Already caught by Randy Dunlap and a
couple others.  Tried to put it somewhere that made sense.

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>