usb: gadget: net2280: Fix typo on #ifdef

Commit e56e69cc ("usb: gadget: net2280: Use pr_* function")
includes a editing mistake on one of the #ifdef.

This patch fixes it.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>