Savedata dialog: serialize ioThreadStatus (bump section to v3)

[Arkadyzja]

What

One-line fix (plus a comment): bump the PSPSaveDialog savestate section from max version 2 to 3, which activates the existing-but-dead s > 2 branch that serializes ioThreadStatus.

The bug

The if (s > 2) { Do(p, ioThreadStatus); } branch in PSPSaveDialog::DoState appears to have been dead code since it was written — the section declaration stayed at p.Section("PSPSaveDialog", 1, 2), so the version can never exceed 2 and every load takes the else path, resetting ioThreadStatus to SAVEIO_NONE.

Consequence: loading a state that was taken while a savedata operation was in flight loses the operation's completion status. Depending on where the dialog's state machine was, it either repeats the IO or waits on a completion that has already happened, instead of resuming from the recorded status.

Why restoring the value is safe

• DoState joins the IO thread (ioThread.join()) before serializing anything, so the value that ends up in the state is only ever SAVEIO_NONE or SAVEIO_DONE — never a mid-operation status.
• The effects of a completed operation are already part of the serialized state (emulated RAM / savedata results), so restoring SAVEIO_DONE is consistent with the rest of the loaded state.

Compatibility

• Old (v2 and v1) states load exactly as before, through the reset path.
• States written by this build won't load on older builds — the usual consequence of a section version bump.