doc: fix typo in vm.runInNewContext() description

PR-URL: https://github.com/nodejs/node/pull/8005
Reviewed-By: Prince John Wesley <princejohnwesley@gmail.com>
Reviewed-By: Minwoo Jung <jmwsoft@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/vm.md

@@ -321,7 +321,7 @@ added: v0.3.1
     before terminating execution. If execution is terminated, an [`Error`][]
     will be thrown.
 
-The `vm.runInContext()` first contextifies the given `sandbox` object (or
+The `vm.runInNewContext()` first contextifies the given `sandbox` object (or
 creates a new `sandbox` if passed as `undefined`), compiles the `code`, runs it
 within the context of the created context, then returns the result. Running code
 does not have access to the local scope.