improve error checking and efficiency of octave audio callback function * audiodevinfo.cc (octave_play_callback): Check for non-null player object. Move computations of constant values outside of loop. Invert nesting of switch statements and loops. Use const pointer to data instead of RowVector::elem method. (portaudio_play_callback): Check for non-null player object.

8728cf80b7d84b0ac401debac5b37217aac0d2e2 gnulib-hg