test: tmpdir creation failures should fail tests

tmpdir creation only happens for tests that need it. So failure to
refresh the temporary directory should result in a failed test.

PR-URL: nodejs#1976
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

test/common.js

@@ -52,15 +52,8 @@ function rmdirSync(p, originalEr) {
 }
 
 exports.refreshTmpDir = function() {
-  try {
-    rimrafSync(exports.tmpDir);
-  } catch (e) {
-  }
-
-  try {
-    fs.mkdirSync(exports.tmpDir);
-  } catch (e) {
-  }
+  rimrafSync(exports.tmpDir);
+  fs.mkdirSync(exports.tmpDir);
 };
 
 if (process.env.TEST_THREAD_ID) {