dgram: scope redeclared variables

A few variables in `lib/dgram.js` are redeclared with `var` in a scope where they have already been declared. These instances can be scoped more narrowly with `const`, so that's what this change does. PR-URL: #4940 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: James M Snell <[email protected]>

Author: Trott

lib/dgram.js

@@ -40,13 +40,13 @@ function lookup6(address, callback){
 
 functionnewHandle(type){
 if(type=='udp4'){
-varhandle=newUDP();
+consthandle=newUDP();
 handle.lookup=lookup4;
 returnhandle;
 }
 
 if(type=='udp6'){
-varhandle=newUDP();
+consthandle=newUDP();
 handle.lookup=lookup6;
 handle.bind=handle.bind6;
 handle.send=handle.send6;
@@ -209,7 +209,7 @@ Socket.prototype.bind = function(port_ /*, address, callback*/){
 if(!self._handle)
 return;// handle has been closed in the mean time
 
-varerr=self._handle.bind(ip,port||0,flags);
+consterr=self._handle.bind(ip,port||0,flags);
 if(err){
 varex=exceptionWithHostPort(err,'bind',ip,port);
 self.emit('error',ex);
@@ -371,7 +371,7 @@ function doSend(ex, self, ip, buffer, address, port, callback){
 !!callback);
 if(err&&callback){
 // don't emit as error, dgram_legacy.js compatibility
-varex=exceptionWithHostPort(err,'send',address,port);
+constex=exceptionWithHostPort(err,'send',address,port);
 process.nextTick(callback,ex);
 }
 }