BeanMidi.loadMessage(buff) off by 3

[joebowbeer]

BeanMidi.loadMessage(buf) return value on buffer full is off by 3.

If full, return the current index. The index should only be incremented if the load was successful.

bean-arduino-core/hardware/bean/avr/cores/bean/BeanMidi.cpp

Line 175 in 6a199a9

idx += 3;