target: Allow PERSISTENT RESERVE IN for non-reservation holder

commit 6816966a8418b980481b4dced7eddd1796b145e8 upstream.

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>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>