Make any keypress work to close the window

Author: cinderblock

win32/rpi-mass-storage-gadget64.bat

@@ -6,4 +6,5 @@ rpiboot -d mass-storage-gadget64
 @echo EMMC/NVMe devices should be visible in the Raspberry Pi Imager in a few seconds.
 @echo For debug, you can login to the device using the USB serial gadget - see COM ports in Device Manager.
 @echo: 
-set /p dummy=Press a key to close this window.
+@echo | set /p dummy=Press a key to close this window.
+@pause > nul