avfilter/internal: Mark ff_filter_get_nb_threads() as av_pure

It does not modify anything; it only returns a value, so it fulfills
the requirements for av_pure.
The deeper rationale behind this change is that this function is called
quite often inside arguments to FFMIN which may lead to two calls to it;
declaring this function as av_pure allows the compiler to optimize the
second call away.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

0 files changed, 0 insertions, 0 deletions