RIOT-OS/RIOT — pull request #1745 by OlegHahm (2014-10-01 16:22:06+00:00)
Title: sixlowpan: fixed net_if counter

This is a fixup for 11254577eb01178b4ca90fe6383987cc0721fca6 which
caused this function to always return a positive number, when any
interfaces was configured.