Fix mismatching C++ new[] / delete calls
cppcheck report:
[rbutil/rbutilqt/base/encoderlame.cpp:273]: (error) Mismatching allocation and deallocation: mp3buf
[rbutil/rbutilqt/base/encoderlame.cpp:282]: (error) Mismatching allocation and deallocation: mp3buf
[rbutil/rbutilqt/base/encoderlame.cpp:289]: (error) Mismatching allocation and deallocation: mp3buf
[rbutil/rbutilqt/base/encoderlame.cpp:274]: (error) Mismatching allocation and deallocation: wavbuf
[rbutil/rbutilqt/base/encoderlame.cpp:283]: (error) Mismatching allocation and deallocation: wavbuf
[rbutil/rbutilqt/base/encoderlame.cpp:290]: (error) Mismatching allocation and deallocation: wavbuf
[rbutil/rbutilqt/base/encoderlame.cpp:184]: (error) Mismatching allocation and deallocation: buf
Change-Id: I9fd54b6e02817eb900ec6e24d967da6d4beaeb27