[PATCH] netpoll: fix netpoll lockup

current -git doesnt boot on my laptop due to netpoll not unlocking the
tx lock in the else branch.

booted this up on my laptop with lockdep enabled and there are no
locking complaints and it works fine.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>