Fix tmp usage in crash reporter setup

Summary:
This happened during startup:
{F237135281}

From `tmp` docs:

> IMPORTANT NOTE: template no longer accepts a path. Use the dir option instead if you require tmp to create your temporary filesystem object in a different place than the default tmp.tmpdir.

Reviewed By: mweststrate

Differential Revision: D21570416

fbshipit-source-id: 170886d0fda5e21cb23fe836fcde33eb457a4c1b

desktop/app/src/utils/electronCrashReporter.tsx

@@ -22,7 +22,7 @@ const tmpName = promisify(tmpNameCallback) as (
 // Cross platform way to find the /tmp directory or equivalent.
 // The tempPath set should be persistent across app restarts.
 const tempPathPromise: Promise<string> = tmpName({
-  template: '/tmp/tmp-XXXXXX',
+  template: 'tmp-XXXXXX',
 }).then((name) => resolve(name, '..', 'flipper'));
 
 export default function initCrashReporter(sessionId: string): Promise<void> {