usb: misc: Update link to EHSET pdf doc

Obviously file on the website was renamed.

Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Link: https://lore.kernel.org/r/20250829161708.106813-1-petr.vorel@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>