MIDI: don't create two of the same device

Devices got created twice because I forgot to remove a
debugging statement

Bug: 220168245
Test: MidiKeyboard and MidiScope
Change-Id: I2bd7b28bec3025e62dce39fcd500350a9ca6de8d
Merged-In: I2bd7b28bec3025e62dce39fcd500350a9ca6de8d
1 file changed