target: Fix return sense reason in target_scsi3_emulate_pr_out

The sense reason should be TCM_PARAMETER_LIST_LENGTH_ERROR when
parmeter length error.

Also the cdb[1] & 0x1f has been assigned to local variable sa,
so use sa instead of it.

Signed-off-by: Tang Wenji <tang.wenji@zte.com.cn>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>