cdrom: fix unused variable warnings if debug is off

libretro-common/cdrom/cdrom.c

@@ -220,6 +220,9 @@ retry:
       unsigned i;
       const char *sense_key_text = NULL;
 
+      (void)sense_key_text;
+      (void)i;
+
       switch (sense[2] & 0xF)
       {
          case 0:

libretro-common/vfs/vfs_implementation_cdrom.c

@@ -68,6 +68,8 @@ int64_t retro_vfs_file_seek_cdrom(libretro_vfs_implementation_file *stream, int6
       unsigned char frame = 0;
       const char *seek_type = "SEEK_SET";
 
+      (void)seek_type;
+
       lba_to_msf(frames, &min, &sec, &frame);
 
       switch (whence)