USB: skeleton: Use dev_info instead of info

338b67b0

 removed the info macro and
replaced its uses with dev_info.  This patch does so for
usb-skeleton.c, which was missed.

Signed-off-by: Matt Kraai <kraai@ftbfs.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>