Clean up E7520/7320/7525 quirk printk.

The printk level in this printk is bogus, as the previous printk
didn't have a terminating \n resulting in ..

Intel E7520/7320/7525 detected.<6>Disabling irq balancing and affinity

It also never printed a \n at all in the case where we didn't do
the quirk.

Change it to only make noise if it actually does something useful.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>