I had no restraint and have helped myself to a White Shark®
"DoubleShock", "PC-compatible", "gaming only", ultra-cheap
game controller.

Nusb/joy complains about not finding a suitable endpoint
because it demands:
	ep->dir == Ein
while my controller happens to report a both-way endpoint.
Allowing the Eboth endpoint makes it work fine, but I don't
know if this could be troublesome for other controllers.

Patch is attached.

-- kvik