[Bridge] [PATCH net-next] bridge: Fix incorrect judgment of promisc

[David Laight]

From: Toshiaki Makita 
> > A quick truth table:
> > 	auto_cnt	auto_port	set/clear
> > 		0		0	clear
> > 		0		1	clear
> > 		1		0	set
> > 		1		1	clear
> > 		2+		0/1	clear
> 
> The last line should be set.

I've clearly not drunk enough coffee today...

I suspect the 0-1 line is impossible.
Since the check is probably for 'any other ports in 'auto' mode'.
So:
	if (auto_cnt - auto_port > 0)
(which is much the same as the original) is a good descriptive test.

	David