Fix infiniband interface names

Reviewed-by: Aleix Boné <abonerib@bsc.es>

m/bay/configuration.nix

@@ -24,7 +24,7 @@
       address = "10.0.40.40";
       prefixLength = 24;
     } ];
-    interfaces.ibp5s0.ipv4.addresses = [ {
+    interfaces.ibs785.ipv4.addresses = [ {
       address = "10.0.42.40";
       prefixLength = 24;
     } ];