Fix all uninitialized variable warnings (C26495)

Source/Core/Core/IOS/ES/ES.h

@@ -377,9 +377,9 @@ private:
   struct OpenedContent
   {
     bool m_opened = false;
-    u64 m_fd;
+    u64 m_fd = 0;
     u64 m_title_id = 0;
-    ES::Content m_content;
+    ES::Content m_content{};
     u32 m_uid = 0;
   };