[SCSI] advansys: misc reformatting

Remove some useless forward declarations
Reformat some comments, debug messages, and the occasional piece of real code
Removal of unnecessary braces
Remove duplicate setting of shost->irq

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>