Rename unused variables to resolve lint warnings

Signed-off-by: Austin Vazquez <macedonv@amazon.com>

plugins/main/ipvlan/ipvlan.go

@@ -334,7 +334,6 @@ func cmdDel(args *skel.CmdArgs) error {
 		}
 		return nil
 	})
-
 	if err != nil {
 		//  if NetNs is passed down by the Cloud Orchestration Engine, or if it called multiple times
 		// so don't return an error if the device is already removed.