Fix setting correct speed value in Kb/s. Fixes #274

Aaru.Core/Devices/Dumping/MMC.cs

@@ -195,11 +195,14 @@ namespace Aaru.Core.Devices.Dumping
 
             if(compactDisc)
             {
+                _speedMultiplier *= 177;
                 CompactDisc();
 
                 return;
             }
 
+            _speedMultiplier *= 150;
+
             var   scsiReader = new Reader(_dev, _dev.Timeout, null, _dumpRaw);
             ulong blocks     = scsiReader.GetDeviceBlocks();
             _dumpLog.WriteLine("Device reports disc has {0} blocks", blocks);