usb: misc: improve dev_printk output

Use the usb_interface's dev member for dev_printk instead of the
usb_device's, as this will help improve kernel logging clarity by
displaying the interface name and number as well as just the USB
bus/device numbers.

Change-Id: I677558fd6c33ee658ef03fdcbb25bb5c0782f77b
Signed-off-by: Jack Pham <jackp@codeaurora.org>