[SCSI] scsi_debug: remove unnecessary function declarations

This patch removes function declarations with moving some
functions. This cleans up them a bit to silence checkpatch.pl. There
is no functional change.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>