nvme: change data type of lba_shift

u8 fits the need, so stop using int for it.
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

drivers/nvme/host/nvme.h

@@ -470,7 +470,7 @@ struct nvme_ns_head {
 	struct nvme_effects_log *effects;
 	u64			nuse;
 	unsigned		ns_id;
-	int			lba_shift;
+	u8			lba_shift;
 	u16			ms;
 	u16			pi_size;
 	u8			pi_type;