doc: fix bug in child_process.spawn() sample code

diff --git a/doc/api/child_process.markdown b/doc/api/child_process.markdown
index 99f72db..6439fce 100644 (file)
--- a/doc/api/child_process.markdown
+++ b/doc/api/child_process.markdown
@@ -306,7 +306,7 @@ Example: A very elaborate way to run 'ps ax | grep ssh'
     });
 
     grep.stdout.on('data', function (data) {
-      console.log(data);
+      console.log('' + data);
     });
 
     grep.stderr.on('data', function (data) {