[Linux] Fix regex to get vfs details properly

Fix regex to get vfs details properly.

Possible outputs from ip link show <PF_name>:
- vf 0 MAC 00:00:00:00:00:00, spoof checking on, link-state auto, trust off, query_rss off
- vf 0     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff, spoof checking on, link-state auto, trust off, query_rss off
