CA-38463: backend vifs now have proper "device" symlinks in /sys so to tell the difference between them and a real "physical" interface, look to see whether they link to devices/xen-backend/...
CA-38463: backend vifs now have proper "device" symlinks in /sys so to tell the difference between them and a real "physical" interface, look to see whether they link to devices/xen-backend/...

This prevents PIF.scan from accidentally introducing vifX.Y as PIFs...

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@eu.citrix.com>

djs55/xcp-networkd,johnelse/xcp-rrdd,koushikcgit/xcp-networkd,robhoes/squeezed,simonjbeaumont/xcp-rrdd,koushikcgit/xcp-rrdd,sharady/xcp-networkd,johnelse/xcp-rrdd,djs55/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-networkd,simonjbeaumont/xcp-rrdd,djs55/xcp-rrdd,djs55/xcp-rrdd,djs55/squeezed,koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd