[Coverity CID :187672] Uninitialized variables in /tests/net/iface/src/main.c

[mandarcthorat1]

Static code scan issues seen in File: /tests/net/iface/src/main.c
Category: Uninitialized variables
Function: select_src_iface
Component: Tests
CID: 187672
Please fix or provide comments to square it off in coverity in the link: https://scan9.coverity.com/reports.htm#v32951/p12996