crush: crush_init_workspace starts with struct crush_work

It is not just a pointer to crush_work, it is the whole structure.
That is not a problem since it only contains a pointer. But it will
be a problem if new data members are added to crush_work.

Reflects ceph.git commit ee957dd431bfbeb6dadaf77764db8e0757417328.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/crush/mapper.c

@@ -858,7 +858,7 @@ void crush_init_workspace(const struct crush_map *map, void *v)
 	 * set the pointer first and then reserve the space for it to
 	 * point to by incrementing the point.
 	 */
-	v += sizeof(struct crush_work *);
+	v += sizeof(struct crush_work);
 	w->work = v;
 	v += map->max_buckets * sizeof(struct crush_work_bucket *);
 	for (b = 0; b < map->max_buckets; ++b) {