b44: Fix wedge when using netconsole.

Fixes kernel bugzilla #14691

Due to the way netpoll works, it is perfectly legal to see
NAPI already scheduled when new device events are pending
in b44_interrupt().

So logging a message about it is wrong and in fact harmful.

Based upon a patch by Andreas Mohr.

Signed-off-by: David S. Miller <davem@davemloft.net>