wavpackenc: proper buffer allocation

The allocation didn't account for headers, that can be easily 79 bytes.
As a result, buffers allocated for a few samples (e.g. 5 in the original
bug) could be undersized.

Fixed ticket #2881.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 2ba58bec20b0039ccc40cfba59af6d56de16e8b1)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
1 file changed