USB: usbfs: fix -ENOENT error code to be -ENODEV

commit 01105a246345f011fde64d24a601090b646e9e4c upstream.

This patch (as1272) changes the error code returned when an open call
for a USB device node fails to locate the corresponding device.  The
appropriate error code is -ENODEV, not -ENOENT.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>