staging: emxx_udc: Fix replace printk(KERN_DEBUG ..) with dev_dbg

This patch fixes "Prefer [subsystem eg: netdev]_dbg([subsystem]dev,
... then dev_dbg(dev, ... then pr_debug(...  to printk(KERN_DEBUG"
checkpatch.pl warning in emxx_udc.c

Changes in v2:
 - Fixed dev_debug function call as dev_dbg

Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>