test: add mustCall to test-fs-readfile-pipe

PR-URL: #27450
Reviewed-By: Yorkie Liu <yorkiefixer@gmail.com>
Reviewed-By: Weijia Wang <starkwang@126.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

Author: tonyhty

test/parallel/test-fs-readfile-pipe.js

@@ -31,10 +31,10 @@ const assert = require('assert');
 constfs=require('fs');
 
 if(process.argv[2]==='child'){
-fs.readFile('/dev/stdin',function(er,data){
+fs.readFile('/dev/stdin',common.mustCall(function(er,data){
 assert.ifError(er);
 process.stdout.write(data);
-});
+}));
 return;
 }
 
@@ -47,7 +47,7 @@ const exec = require('child_process').exec;
 constf=JSON.stringify(__filename);
 constnode=JSON.stringify(process.execPath);
 constcmd=`cat ${filename} | ${node}${f} child`;
-exec(cmd,function(err,stdout,stderr){
+exec(cmd,common.mustCall(function(err,stdout,stderr){
 assert.ifError(err);
 assert.strictEqual(
 stdout,
@@ -58,4 +58,4 @@ exec(cmd, function(err, stdout, stderr) {
 '',
 `expected not to read anything from stderr but got: '${stderr}'`);
 console.log('ok');
-});
+}));