SCUMM: Fix bug #6009 "DC: FT/Dig - Sound disappears when VMU save fails"

This was introduced by fd3970aa52a0c7f411afdddfebad208f783281c8:
Apply patch #2984508 - "GSoC: SCUMM stopped audio from playing while
saving"

This was not quite correct as if the save fails, the function exits
without unpausing the engine, which resulted in sound and music
remaining muted. This corrects the logic to unpause in all cases.