nvme.h: fixup ANA group descriptor format

ANA Phase 3 draft had the 'reserved' field in the group descriptor
format set to '23:17' (so that the first namespace identifier started
at byte 24), but that got move with the approved TP to '31:17'
(so that the first namespace identifier started at byte 32).
Signed-off-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

include/linux/nvme.h

@@ -446,7 +446,7 @@ struct nvme_ana_group_desc {
 	__le32	nnsids;
 	__le64	chgcnt;
 	__u8	state;
-	__u8	rsvd17[7];
+	__u8	rsvd17[15];
 	__le32	nsids[];
 };