USB: m66592-udc: Fix up dev_set_name() badness.

Commit 0031a06e converted all of the USB
drivers to use dev_set_name(), though there was a typo on the m66592-udc
conversion that handed off the wrong pointer (we want the struct device
here obviously, not the struct usb_gadget).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>