filter: Fixes CID 1046198

d_fft allocated in the constructor wasn't freed in the destructor.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
vocoder: Fixes CID 1043299. Simple unitialized variable.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Merge branch 'maint'