sheep: Shut up "warning: unused variable ‘rw’"

Without this, I got a message below when building:

>   CC       recovery.o
> recovery.c: In function ‘prepare_schedule_oid’:
> recovery.c:648:24: warning: unused variable ‘rw’ [-Wunused-variable]
>   struct recovery_work *rw;
>                         ^

Note that this is only for stable-0.9, not for master.

Signed-off-by: Takashi Menjo <menjo.takashi@lab.ntt.co.jp>

sheep/recovery.c

@@ -645,7 +645,6 @@ static inline void prepare_schedule_oid(uint64_t oid)
 {
 	struct recovery_info *rinfo = main_thread_get(current_rinfo);
 
-	struct recovery_work *rw;
 	struct recovery_obj_work *row;
 
 	if (xlfind(&oid, rinfo->prio_oids, rinfo->nr_prio_oids, oid_cmp)) {