Depending on input chunk size noticable corrpution was hearable, here is an
example command line:

ffplay -f lavfi -i "sine=440:r=8000:samples_per_frame=32,aresample=24000:filter_size=1:phase_shift=0"

Fix this by rounding the fixed point fractions up instead of down.
Signed-off-by: Marton Balint <cus@passwd.hu>