Fix next-hop discovery with multiple devices
Fix next-hop discovery with multiple devices

Fixes https://github.com/Igalia/snabb/issues/1014.

dpino/snabbswitch,SnabbCo/snabbswitch,eugeneia/snabb,alexandergall/snabbswitch,Igalia/snabb,eugeneia/snabbswitch,eugeneia/snabbswitch,eugeneia/snabb,Igalia/snabb,snabbco/snabb,Igalia/snabb,eugeneia/snabb,Igalia/snabbswitch,eugeneia/snabb,alexandergall/snabbswitch,snabbco/snabb,dpino/snabb,Igalia/snabb,Igalia/snabbswitch,eugeneia/snabb,SnabbCo/snabbswitch,Igalia/snabb,Igalia/snabbswitch,dpino/snabb,Igalia/snabb,dpino/snabbswitch,Igalia/snabbswitch,snabbco/snabb,alexandergall/snabbswitch,snabbco/snabb,alexandergall/snabbswitch,eugeneia/snabbswitch,dpino/snabb,dpino/snabb,eugeneia/snabb,SnabbCo/snabbswitch,SnabbCo/snabbswitch,alexandergall/snabbswitch,eugeneia/snabb,Igalia/snabb,dpino/snabbswitch,snabbco/snabb,eugeneia/snabbswitch,dpino/snabb,eugeneia/snabb,alexandergall/snabbswitch,dpino/snabb,snabbco/snabb,Igalia/snabb,snabbco/snabb,dpino/snabbswitch,alexandergall/snabbswitch,alexandergall/snabbswitch,Igalia/snabbswitch,snabbco/snabb,dpino/snabb