block/vhdx: drop unallocated_blocks_are_zero

vhdx doesn't have .bdrv_co_block_status handler, so DATA|ALLOCATED is
always assumed for it in bdrv_co_block_status().
unallocated_blocks_are_zero is useless (it doesn't affect the only user
of the field: bdrv_co_block_status()), drop it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Max Reitz <[email protected]>

Author: Vladimir Sementsov-Ogievskiy

block/vhdx.c

@@ -1164,9 +1164,6 @@ static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 
     bdi->cluster_size = s->block_size;
 
-    bdi->unallocated_blocks_are_zero =
-        (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0;
-
     return 0;
 }