DiscIO: Fix NAND Memory Leak

CNANDContentData is a base class with a non-virtual destructor so
derived classes don't get destroyed causing them to leak resources.

Source/Core/DiscIO/NANDContentLoader.cpp

@@ -29,6 +29,8 @@
 
 namespace DiscIO
 {
+CNANDContentData::~CNANDContentData() = default;
+
 CSharedContent::CSharedContent()
 {
   UpdateLocation();