Be less verbose when opening a pipe and print the endpoint & slot when submitting a command.  No change for non-XHCI_DEBUG kernel.
Be less verbose when opening a pipe and print the endpoint & slot
when submitting a command.  No change for non-XHCI_DEBUG kernel.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars