Prevent path traversal in NANDImporter::ProcessEntry

Reported by MrSynAckster. A specifically crafted NAND dump could use
path traversal to overwrite files on the host file system.

This is also an accuracy fix for importing NAND dumps that contain
file names that Dolphin is supposed to escape. Some games' save files
are affected.

Source/Core/DiscIO/NANDImporter.cpp

@@ -11,6 +11,7 @@
 #include "Common/IOFile.h"
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
+#include "Common/NandPaths.h"
 #include "Core/IOS/ES/Formats.h"
 
 namespace DiscIO
@@ -134,7 +135,7 @@ bool NANDImporter::ExtractFiles()
 std::string NANDImporter::GetPath(const NANDFSTEntry& entry, const std::string& parent_path)
 {
   std::string name(entry.name, strnlen(entry.name, sizeof(NANDFSTEntry::name)));
-  return parent_path + '/' + name;
+  return parent_path + '/' + Common::EscapeFileName(name);
 }
 
 bool NANDImporter::ProcessEntry(u16 entry_number, const std::string& parent_path)