block/file-posix: drop unallocated_blocks_are_zero

raw_co_block_status() in block/file-posix.c never returns 0, so
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/file-posix.c

@@ -2878,9 +2878,6 @@ static int coroutine_fn raw_co_pwrite_zeroes(
 
 static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 {
-    BDRVRawState *s = bs->opaque;
-
-    bdi->unallocated_blocks_are_zero = s->discard_zeroes;
     return 0;
 }