Bridge flooding: fix typo in rule evaluation

Bug introduced in the recent "remove-port-sets" patch.

Change-Id: I1e4895aa16c9917945d24e9254921a0160ed21fa
Signed-off-by: Guillermo Ontanon <guillermo@midokura.jp>
Merge "Bridge flooding: fix typo in rule evaluation" into staging/v2014.11