Update exactone diff.

cgminer.c

@@ -2610,7 +2610,7 @@ static inline struct pool *select_pool(bool lagging)
 	return pool;
 }
 
-static double DIFFEXACTONE = 26959946667150639794667015087019630673637144422540572481103610249216.0;
+static double DIFFEXACTONE = 26959946667150639794667015087019630673637144422540572481103610249215.0;
 
 /*
  * Calculate the work share difficulty

util.c

@@ -1522,8 +1522,11 @@ bool initiate_stratum(struct pool *pool)
 		applog(LOG_INFO, "Failed to get nonce1 in initiate_stratum");
 		goto out;
 	}
+
+	cg_wlock(&pool->data_lock);
 	pool->n1_len = strlen(pool->nonce1) / 2;
 	pool->n2size = json_integer_value(json_array_get(res_val, 2));
+	cg_wunlock(&pool->data_lock);
 	if (!pool->n2size) {
 		applog(LOG_INFO, "Failed to get n2size in initiate_stratum");
 		goto out;