lavu/opencl_internal: use av_opencl_errstr

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavfi/unsharp_opencl: use av_opencl_errstr

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Remove a superfluous include from libavcodec/options_table.h.