test: cleanup test-dgram-error-message-address

* var -> const
* assert.equal() -> assert.strictEqual()
* assert.notEqual() -> assert.notStrictEqual()
Fixes: #8925
PR-URL: #8938
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

Author: Goyapa

test/parallel/test-dgram-error-message-address.js

@@ -1,35 +1,35 @@
 'use strict';
-varcommon=require('../common');
-varassert=require('assert');
-vardgram=require('dgram');
+constcommon=require('../common');
+constassert=require('assert');
+constdgram=require('dgram');
 
 // IPv4 Test
-varsocket_ipv4=dgram.createSocket('udp4');
+constsocket_ipv4=dgram.createSocket('udp4');
 
 socket_ipv4.on('listening',common.fail);
 
 socket_ipv4.on('error',common.mustCall(function(e){
 assert.strictEqual(e.port,undefined);
-assert.equal(e.message,'bind EADDRNOTAVAIL 1.1.1.1');
-assert.equal(e.address,'1.1.1.1');
-assert.equal(e.code,'EADDRNOTAVAIL');
+assert.strictEqual(e.message,'bind EADDRNOTAVAIL 1.1.1.1');
+assert.strictEqual(e.address,'1.1.1.1');
+assert.strictEqual(e.code,'EADDRNOTAVAIL');
 socket_ipv4.close();
 }));
 
 socket_ipv4.bind(0,'1.1.1.1');
 
 // IPv6 Test
-varsocket_ipv6=dgram.createSocket('udp6');
+constsocket_ipv6=dgram.createSocket('udp6');
 
 socket_ipv6.on('listening',common.fail);
 
 socket_ipv6.on('error',common.mustCall(function(e){
 // EAFNOSUPPORT or EPROTONOSUPPORT means IPv6 is disabled on this system.
-varallowed=['EADDRNOTAVAIL','EAFNOSUPPORT','EPROTONOSUPPORT'];
-assert.notEqual(allowed.indexOf(e.code),-1);
+constallowed=['EADDRNOTAVAIL','EAFNOSUPPORT','EPROTONOSUPPORT'];
+assert.notStrictEqual(allowed.indexOf(e.code),-1);
 assert.strictEqual(e.port,undefined);
-assert.equal(e.message,'bind '+e.code+' 111::1');
-assert.equal(e.address,'111::1');
+assert.strictEqual(e.message,'bind '+e.code+' 111::1');
+assert.strictEqual(e.address,'111::1');
 socket_ipv6.close();
 }));