target: Allow PERSISTENT RESERVE IN for non-reservation holder

Initiators that aren't the active reservation holder should be able to
do a PERSISTENT RESERVE IN command in all cases, so add it to the list
of allowed CDBs in core_scsi3_pr_seq_non_holder().

Signed-off-by: Marco Sanvido <marco@purestorage.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_pr.c

@@ -478,6 +478,7 @@ static int core_scsi3_pr_seq_non_holder(
 	case READ_MEDIA_SERIAL_NUMBER:
 	case REPORT_LUNS:
 	case REQUEST_SENSE:
+	case PERSISTENT_RESERVE_IN:
 		ret = 0; /*/ Allowed CDBs */
 		break;
 	default: