Added missing return keyword for undefined result

Author: gitdagray

next04/lib/getUserPosts.tsx

@@ -1,7 +1,7 @@
 export default async function getUserPosts(userId: string) {
     const res = await fetch(`https://jsonplaceholder.typicode.com/posts?userId=${userId}`, { next: { revalidate: 60 } })
 
-    if (!res.ok) undefined
+    if (!res.ok) return undefined
 
     return res.json()
 }