scsi2sd-util6 fix for detecting boards under Windows without an SD card inserted

lib/SCSI2SD/CHANGELOG

@@ -1,3 +1,12 @@
+20210503        6.4.2
+    - Bug fix for errors while writing data
+    - Fix for scsi2sd-util6 under Windows which may fail to detect a board without a SD card inserted.
+
+20210426		6.4.1
+    - 2021 hardware support release.
+    - scsi2sd-util6 stability improvements (contributed by Jonathan Wakely.
+
+
 20201012		6.3.2
 	- Increase limit of READ/WRITE BUFFER command for improved compatibility
 	SGI Iris hosts

lib/SCSI2SD/src/scsi2sd-util6/SCSI2SD_HID.cc

@@ -301,6 +301,10 @@ HID::sendHIDPacket(
 		for (int retry = 0; retry < 10 && result <= 0; ++retry)
 		{
 			result = hid_write(myConfigHandle, reportBuf, sizeof(reportBuf));
+            if (result <= 0)
+            {
+                wxMilliSleep(32);
+            }
 		}
 
 		if (result <= 0)
@@ -322,6 +326,10 @@ HID::sendHIDPacket(
 		readHID(hidBuf, sizeof(hidBuf)); // Will block
 		hidPacket_recv(hidBuf, HID_PACKET_SIZE);
 		resp = hidPacket_getPacket(&respLen);
+        if (!resp)
+        {
+            wxMilliSleep(32);
+        }
 	}
 
 	if (!resp)