Fix revive linter errors

Golangci-lint is now running version 1.52.1. This introduced some errors.

Signed-off-by: Marcelo Guerrero Viveros <marguerr@redhat.com>

plugins/ipam/static/main.go

@@ -276,7 +276,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 	return types.PrintResult(result, confVersion)
 }
 
-func cmdDel(args *skel.CmdArgs) error {
+func cmdDel(_ *skel.CmdArgs) error {
 	// Nothing required because of no resource allocation in static plugin.
 	return nil
 }