[SCSI] iscsi: Use struct scsi_lun in iscsi structs instead of u8[8]

struct scsi_lun is also just a struct with an array of 8 octets (64 bits)
but using it instead in iscsi structs lets us call scsilun_to_int
without a cast, and also lets us copy it using assignment, instead of
memcpy().

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 0f43677..cedcff3 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -115,7 +115,7 @@
 	/* copied values in case we need to send tmfs */
 	itt_t			hdr_itt;
 	__be32			cmdsn;
-	uint8_t			lun[8];
+	struct scsi_lun		lun;
 
 	int			itt;		/* this ITT */