kernel - Fix CAM peripheral error handling

kernel - Fix CAM peripheral error handling

* cam_periph.c was bcopy()ing the *ENTIRE* saved ccb back to the
  original when working through certain error results.  This completely
  destroys linked list entry fields.

* Refactor by hacking a restore_ccb() function which does not copy
  over the link list entry fields or the callout structure.

* Fixes panics with CDs, particularly audio CDs, and can also fix
  other panics.

  Panics are related to situations where an AHCI error or errors occur
  while multiple CCBs are queued.

* Also always initialize the state tracking field for various scsi
  periphals to ensure that stale data does not result in improper
  processing in scsi/*.c's *done() functions.

Reported-by: htse