rtmidi: Use proper integer types
rtmidi: Use proper integer types

Begasus/haikuports,Begasus/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,haikuports/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,Begasus/haikuports