If no volume label is found, and the current system is PSX or PS2, use the PlayStation serial as the volume label instead of "track"
I initially tried for PS3/PS4/PS5 as well, but those systems have a default volume label ("PS3VOLUME" etc), so there is no point doing this for those systems.
If no volume label is found, and the current system is PSX or PS2, use the PlayStation serial as the volume label instead of "track" I initially tried for PS3/PS4/PS5 as well, but those systems have a default volume label ("PS3VOLUME" etc), so there is no point doing this for those systems.
Fixes #494