[patches] rename dev to DEVICE in freifunk-policyrouting hotplug script

This should fix #46 and add the policy once the device is up.
The dev variable was empty. Netifd provides a DEVICE variable to
hotplug/handler scripts.

http://git.openwrt.org/?p=project/netifd.git;a=commit;h=3ff220f1861f76ddfeb1aebc61ffbaf14b6d60df
[patches] fix name of freifunk-policyrouting-hotplug-device patch
Merge branch 'master' into bug/freifunk-policyrouting-hotplug
Merge branch 'master' into bug/freifunk-policyrouting-hotplug
Merge pull request #48 from freifunk-berlin/bug/freifunk-policyrouting-hotplug

Bug/freifunk policyrouting hotplug