Store how many work items are worked on per pool.

cgminer.c

@@ -4268,6 +4268,7 @@ static void stage_work(struct work *work)
 	applog(LOG_DEBUG, "Pushing work from pool %d to hash queue", work->pool->pool_no);
 	work->work_block = work_block;
 	test_work_current(work);
+	work->pool->works++;
 	hash_push(work);
 }
 

miner.h

@@ -1271,6 +1271,7 @@ struct pool {
 	int quota;
 	int quota_gcd;
 	int quota_used;
+	int works;
 
 	double diff_accepted;
 	double diff_rejected;