- addresses the reported bug (with GFP_KERNEL -> GFP_ATOMIC)
  - improves error checking, and
  - is a subset of the changes to scsi_debug in lk 2.6.21-rc*

Compiled and lightly tested (in lk 2.6.21-rc2 environment).
Signed-off-by: Douglas Gilbert <dougg@torque.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>