src: validate args length in Access and Close

This is a follow-up of nodejs#17914. When
Access and Close functions are called in Sync mode, the number of items
in args is validated. These are the only two places in this file where
this validation doesn't take place.

PR-URL: nodejs#18203
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

src/node_file.cc

@@ -403,6 +403,7 @@ void Access(const FunctionCallbackInfo<Value>& args) {
     AsyncCall(env, args, "access", UTF8, AfterNoArgs,
               uv_fs_access, *path, mode);
   } else {  // access(path, mode, undefined, ctx)
+    CHECK_EQ(args.Length(), 4);
     fs_req_wrap req_wrap;
     SyncCall(env, args[3], &req_wrap, "access", uv_fs_access, *path, mode);
   }
@@ -424,6 +425,7 @@ void Close(const FunctionCallbackInfo<Value>& args) {
     AsyncCall(env, args, "close", UTF8, AfterNoArgs,
               uv_fs_close, fd);
   } else {  // close(fd, undefined, ctx)
+    CHECK_EQ(args.Length(), 3);
     fs_req_wrap req_wrap;
     SyncCall(env, args[2], &req_wrap, "close", uv_fs_close, fd);
   }