musb-new: Properly remove a transfer from the schedule on timeout

If a transfer / urb times-out, properly remove it from the schedule, rather
then letting it sit on the ep head. This stops the musb code from getting
confused and refusing to queue further transfers after a timeout.

Tested by unplugging a usb-keyboard, replugging it and doing a usb-reset,
before this commit the keyboard would not work after the usb-reset.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>