udf: Remove unused s_extLength from udf_bitmap

s_extLength was assigned to but the value was never really used. So
just remove the field.
Signed-off-by: Jan Kara <jack@suse.cz>

fs/udf/super.c

@@ -1080,8 +1080,6 @@ static int udf_fill_partdesc_info(struct super_block *sb,
 		if (!bitmap)
 			return 1;
 		map->s_uspace.s_bitmap = bitmap;
-		bitmap->s_extLength = le32_to_cpu(
-				phd->unallocSpaceBitmap.extLength);
 		bitmap->s_extPosition = le32_to_cpu(
 				phd->unallocSpaceBitmap.extPosition);
 		map->s_partition_flags |= UDF_PART_FLAG_UNALLOC_BITMAP;
@@ -1116,8 +1114,6 @@ static int udf_fill_partdesc_info(struct super_block *sb,
 		if (!bitmap)
 			return 1;
 		map->s_fspace.s_bitmap = bitmap;
-		bitmap->s_extLength = le32_to_cpu(
-				phd->freedSpaceBitmap.extLength);
 		bitmap->s_extPosition = le32_to_cpu(
 				phd->freedSpaceBitmap.extPosition);
 		map->s_partition_flags |= UDF_PART_FLAG_FREED_BITMAP;

fs/udf/udf_sb.h

@@ -80,7 +80,6 @@ struct udf_virtual_data {
 };
 
 struct udf_bitmap {
-	__u32			s_extLength;
 	__u32			s_extPosition;
 	int			s_nr_groups;
 	struct buffer_head 	*s_block_bitmap[0];