Error compiling libvmaf filter in MinGW

[Gyan]

Compiling libvmaf filter fails on Windows using GCC 6.3.0 on MinGW64

CC      libavfilter/vf_libvmaf.o
libavfilter/vf_libvmaf.c: In function 'call_vmaf':
libavfilter/vf_libvmaf.c:173:1: error: no return statement in function returning non-void [-Werror=return-type]

Existing function body is

 static void *call_vmaf(void *ctx)
{
    LIBVMAFContext *s = (LIBVMAFContext *) ctx;
    compute_vmaf_score(s);
    av_log(ctx, AV_LOG_INFO, "VMAF score: %f\n",s->vmaf_score);
    pthread_exit(NULL);
}

Adding return NULL; results in successful compilation.

-Werror=return-type is set in configure so I assume that shouldn't be changed.

[Gyan]

Fixed in df3222d4bb18cbceda443def17b1b29067ed6e3f