qcow2: Use offset_into_cluster()

There's a couple of places left in the qcow2 code that still do the
calculation manually, so let's replace them.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/qcow2.c

@@ -367,7 +367,7 @@ static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
                 return -EINVAL;
             }
 
-            if (bitmaps_ext.bitmap_directory_offset & (s->cluster_size - 1)) {
+            if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) {
                 error_setg(errp, "bitmaps_ext: "
                                  "invalid bitmap directory offset");
                 return -EINVAL;
@@ -1959,9 +1959,8 @@ static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,
 {
     BDRVQcow2State *s = bs->opaque;
     uint64_t cluster_offset;
-    int index_in_cluster, ret;
     unsigned int bytes;
-    int status = 0;
+    int ret, status = 0;
 
     qemu_co_mutex_lock(&s->lock);
 
@@ -1982,8 +1981,7 @@ static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,
 
     if ((ret == QCOW2_CLUSTER_NORMAL || ret == QCOW2_CLUSTER_ZERO_ALLOC) &&
         !s->crypto) {
-        index_in_cluster = offset & (s->cluster_size - 1);
-        *map = cluster_offset | index_in_cluster;
+        *map = cluster_offset | offset_into_cluster(s, offset);
         *file = s->data_file->bs;
         status |= BDRV_BLOCK_OFFSET_VALID;
     }