stream: refactor redeclared variables

`lib/_stream_readable.js` contained three instances of `var` declarations occurring twice in the same scope. Refactored to `const` or `let` as appropriate. PR-URL: #4816 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Colin Ihrig <[email protected]>

Author: Trott

lib/_stream_readable.js

@@ -130,10 +130,10 @@ function readableAddChunk(stream, state, chunk, encoding, addToFront){
 onEofChunk(stream,state);
 }elseif(state.objectMode||chunk&&chunk.length>0){
 if(state.ended&&!addToFront){
-vare=newError('stream.push() after EOF');
+conste=newError('stream.push() after EOF');
 stream.emit('error',e);
 }elseif(state.endEmitted&&addToFront){
-vare=newError('stream.unshift() after end event');
+conste=newError('stream.unshift() after end event');
 stream.emit('error',e);
 }else{
 if(state.decoder&&!addToFront&&!encoding)
@@ -640,13 +640,13 @@ Readable.prototype.unpipe = function(dest){
 state.pipesCount=0;
 state.flowing=false;
 
-for(vari=0;i<len;i++)
+for(leti=0;i<len;i++)
 dests[i].emit('unpipe',this);
 returnthis;
 }
 
 // try to find the right one.
-vari=state.pipes.indexOf(dest);
+consti=state.pipes.indexOf(dest);
 if(i===-1)
 returnthis;
 
@@ -847,7 +847,7 @@ function fromList(n, state){
 if(n<list[0].length){
 // just take a part of the first list item.
 // slice is the same for buffers and strings.
-varbuf=list[0];
+constbuf=list[0];
 ret=buf.slice(0,n);
 list[0]=buf.slice(n);
 }elseif(n===list[0].length){
@@ -863,7 +863,7 @@ function fromList(n, state){
 
 varc=0;
 for(vari=0,l=list.length;i<l&&c<n;i++){
-varbuf=list[0];
+constbuf=list[0];
 varcpy=Math.min(n-c,buf.length);
 
 if(stringMode)