Fix bug that caused multi byte MIDI messages to get corrupted when a single real time byte is inserted.
Fix bug that caused multi byte MIDI messages to get corrupted
when a single real time byte is inserted.

From Alexandre Ratchov.  While I don't have a umidi device to
test here it looks correct to me and alex has a history of sending
good MIDI diffs.

ok deraadt@

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars