md: fix some comments.

1/ Raid5 has learned to take over also raid4 and raid6 arrays.
2/ new_chunk in mdp_superblock_1 is in sectors, not bytes.
Signed-off-by: NeilBrown <neilb@suse.de>

drivers/md/raid5.c

@@ -5231,8 +5231,6 @@ static void *raid5_takeover(mddev_t *mddev)
 	 *  raid1 - if there are two drives.  We need to know the chunk size
 	 *  raid4 - trivial - just use a raid4 layout.
 	 *  raid6 - Providing it is a *_6 layout
-	 *
-	 * For now, just do raid1
 	 */
 
 	if (mddev->level == 1)

include/linux/raid/md_p.h

@@ -232,7 +232,7 @@ struct mdp_superblock_1 {
 	__le64	reshape_position;	/* next address in array-space for reshape */
 	__le32	delta_disks;	/* change in number of raid_disks		*/
 	__le32	new_layout;	/* new layout					*/
-	__le32	new_chunk;	/* new chunk size (bytes)			*/
+	__le32	new_chunk;	/* new chunk size (512byte sectors)		*/
 	__u8	pad1[128-124];	/* set to 0 when written */
 
 	/* constant this-device information - 64 bytes */