t10-pi: Move opencoded contants to common header

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/include/linux/t10-pi.h b/include/linux/t10-pi.h
index 9375d23..635a3c5 100644
--- a/include/linux/t10-pi.h
+++ b/include/linux/t10-pi.h
@@ -33,6 +33,8 @@ struct t10_pi_tuple {
 	__be32 ref_tag;		/* Target LBA or indirect LBA */
 };
 
+#define T10_PI_APP_ESCAPE cpu_to_be16(0xffff)
+#define T10_PI_REF_ESCAPE cpu_to_be32(0xffffffff)
 
 extern const struct blk_integrity_profile t10_pi_type1_crc;
 extern const struct blk_integrity_profile t10_pi_type1_ip;