[SCSI] mpt2sas: Fixed some of the comment

Fixed some of the comments sections for some of the function so "@ioc:
pointer to scsi command object" was changed to "@ioc: per adapter object"

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: Eric Moore <Eric.moore@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>