Icarus: Tune timeout hashrate guess based on 7500-sample testing

driver-icarus.c

@@ -297,12 +297,12 @@ static uint64_t icarus_scanhash(struct thr_info *thr, struct work *work,
 	work->blk.nonce = 0xffffffff;
 
 	if (nonce == 0 && ret) {
-		if (unlikely(diff.tv_sec > 12 || (diff.tv_sec == 11 && diff.tv_usec > 300067)))
+		if (unlikely(diff.tv_sec > 12 || (diff.tv_sec == 11 && diff.tv_usec > 389666)))
 			return 0xffffffff;
 		// Approximately how much of the nonce Icarus scans in 1 second...
 		// 0x16a7a561 would be if it was exactly 380 MH/s
-		// 0x168b7b4b was the average over a 201-sample period based on time to find actual shares
-		return (0x168b7b4b * diff.tv_sec) + (0x17a * diff.tv_usec);
+		// 0x167a09b3 was the average over a 7500-sample period based on time to find actual shares
+		return (0x167a09b3 * diff.tv_sec) + (0x179 * diff.tv_usec);
 	}
 
 #ifndef __BIG_ENDIAN__