doc: fix typo in child_process documentation

TSCP should be TCP

PR-URL: #5474
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

doc/api/child_process.markdown

@@ -808,7 +808,7 @@ used to implement flow control.
 #### Example: sending a server object
 
 The `sendHandle` argument can be used, for instance, to pass the handle of
-a TSCP server object to the child process as illustrated in the example below:
+a TCP server object to the child process as illustrated in the example below:
 
 ```js
 const child = require('child_process').fork('child.js');