Fixes "Edit files…" for any game image that isn't on internal storage.
- Editing an image on a USB or external drive failed immediately with
journal the edit session on the console: FS_WRITE_BYTES failed: open_failed. An edit session records itself on the console so an
interrupted edit can still be finished, and that record always lives on
/data— but the folder holding it was only ever created on the drive
the image was on. For an image on/mnt/usb0or/mnt/ext1the two
are different drives, so the record had nowhere to go and the edit
never started. Images on internal storage were unaffected, which is
why this got through testing.