test: fix issues for space-in-parens ESLint rule

PR-URL: https://github.com/nodejs/node/pull/4753
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>

test/parallel/test-process-binding.js

@@ -12,7 +12,7 @@ assert.throws(
 assert.doesNotThrow(function() {
   process.binding('buffer');
 }, function(err) {
-  if ( (err instanceof Error) ) {
+  if (err instanceof Error) {
     return true;
   }
 }, 'unexpected error');