cellSaveData: Skip directory items in savedata_get_list_item

rpcs3/Emu/Cell/Modules/cellSaveData.cpp

@@ -1984,6 +1984,11 @@ static NEVER_INLINE error_code savedata_get_list_item(vm::cptr<char> dirName, vm
 
 		for (const auto& entry : fs::dir(save_path))
 		{
+			if (entry.is_directory)
+			{
+				continue;
+			}
+
 			size_kbytes += ::narrow<u32>((entry.size + 1023) / 1024); // firmware rounds this value up
 		}