fix crash due to wrong placed return
fix crash due to wrong placed return

always returned after fist append. this in turn caused the pending buffer
to be no longer a multiple of the channel count ultimately leading to
a mismatch between per-channel buffer sizes (as catched by the
assert introduced 2 commits ago)

BUG: 279791

KDE/phonon-gstreamer,shadeslayer/phonon-gstreamer,shadeslayer/phonon-gstreamer,KDE/phonon-gstreamer,shadeslayer/phonon-gstreamer