Add more comments explaining how sleep time equals wait time and simplify the

comparison.

driver-bitforce.c

@@ -368,12 +368,14 @@ static uint64_t bitforce_get_result(struct thr_info *thr, struct work *work)
 		if (!pdevbuf[0])           /* Only return if we got nothing after timeout - there still may be results */
 			return 1;
 	} else if (!strncasecmp(pdevbuf, "N", 1)) {/* Hashing complete (NONCE-FOUND or NO-NONCE) */
-		    /* Simple timing adjustment */
+		    /* Simple timing adjustment. Allow a few polls to cope with
+		     * OS timer delays being variably reliable. wait_ms will
+		     * always equal sleep_ms when we've waited greater than or
+		     * equal to the result return time.*/
 	        delay_time_ms = bitforce->sleep_ms;
 		if (bitforce->wait_ms > bitforce->sleep_ms + (WORK_CHECK_INTERVAL_MS * 2))
 			bitforce->sleep_ms += (bitforce->wait_ms - bitforce->sleep_ms) / 2;
-		else if (bitforce->wait_ms > bitforce->sleep_ms - WORK_CHECK_INTERVAL_MS &&
+		else if (bitforce->wait_ms == bitforce->sleep_ms)
-			 bitforce->wait_ms <= bitforce->sleep_ms)
 				bitforce->sleep_ms -= BITFORCE_CHECK_INTERVAL_MS;
 
 		if (delay_time_ms != bitforce->sleep_ms)