CDROM: Store filename, reduce ack cycles

src/common/cd_image_bin.cpp

@@ -24,6 +24,7 @@ CDImageBin::~CDImageBin()
 
 bool CDImageBin::Open(const char* filename)
 {
+  m_filename = filename;
   m_fp = std::fopen(filename, "rb");
   if (!m_fp)
   {

src/common/cd_image_cuesheet.cpp

@@ -63,6 +63,7 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
 
   // get the directory of the filename
   std::string basepath = GetPathDirectory(filename);
+  m_filename = filename;
 
   u32 disc_lba = 0;