Grep the output from 'ip route' command matching first word after match.
The OVS was fixed some time ago, but in new linuxbridge the default
tunnel interface was following wrong grep expression.
Making both OVS and linuxbridge to follow the same reg exp.
Change-Id: I222d694b06285d5ec3d848ee157542796dfc1cc7
Closes-Bug: #1700323