avfilter/showcqt: BASEFREQ and ENDFREQ cast to double

fix default basefreq/endfreq comparison
on platform that does not do comparison
in double type

found on zeranoe 32-bit build, where
default freq range is detected as non-default

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavfilter/avf_showcqt.c

@@ -466,7 +466,7 @@ static int init_axis_color(ShowCQTContext *s, AVFrame *tmp)
     double *freq = NULL;
     int x, y, ret;
 
-    if (s->basefreq != BASEFREQ || s->endfreq != ENDFREQ) {
+    if (s->basefreq != (double) BASEFREQ || s->endfreq != (double) ENDFREQ) {
         av_log(s->ctx, AV_LOG_WARNING, "font axis rendering is not implemented in non-default frequency range,"
                " please use axisfile option instead.\n");
         return AVERROR(EINVAL);