Fix alloc-dealloc-mismatch in StreamReader
Fix alloc-dealloc-mismatch in StreamReader

StreamReader::readCallback always allocates buffer using new[] but the
deletion was done in StreamReader::readDoneCallback with a mismatching
delete.

REVIEW: 120433

BinChengfei/phonon-vlc,KDE/phonon-vlc,KDE/phonon-vlc,BinChengfei/phonon-vlc,KDE/phonon-vlc,BinChengfei/phonon-vlc