[SCSI] call correct scsi_done function in scsi_dispatch_cmd

scsi_dispatch_cmd currently calls scsi_done when the device is in the
SDEV_DEL state, but at this point the command has not had a timer added 
to it (this is done a couple lines down) so scsi_done just returns and 
the command is lost. The attached patch made against 2.6.12-rc3 calls 
__scsi_done in this case so the comamnd will be returned upwards.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>