Remove reshard_abort

src/blockstore/blockstore_impl.h

@@ -191,7 +191,6 @@ public:
 
     void* reshard_start(pool_id_t pool, uint32_t pg_count, uint32_t pg_stripe_size, uint64_t chunk_limit);
     bool reshard_continue(void *reshard_state, uint64_t chunk_limit);
-    void reshard_abort(void *reshard_state);
 
     // Event loop
     void loop();