miekg/pcap — pull request #6 by alicebob (2013-09-28 19:00:27+00:00)
Title: Fix nil pointer derefernce for tunnel device

Fix for a nil de-reference in FindAllDevs() for tunnel devices such as this one:
```
tun0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet addr:46.246.47.79 P-t-P:46.246.47.79 Mask:255.255.255.0
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:3454 errors:0 dropped:0 overruns:0 frame:0
TX packets:61188 errors:0 dropped:56249 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:1495075 (1.4 MiB) TX bytes:86419971 (82.4 MiB)
```