swresample/swresample: Remove "less than" comparissions of enums

Found-by: wm4
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libswresample/swresample.c

@@ -213,10 +213,10 @@ av_cold int swr_init(struct SwrContext *s){
                  s->rematrix_custom;
 
     if(s->int_sample_fmt == AV_SAMPLE_FMT_NONE){
-        if(   av_get_planar_sample_fmt(s-> in_sample_fmt) <= AV_SAMPLE_FMT_S16P
-           && av_get_planar_sample_fmt(s->out_sample_fmt) <= AV_SAMPLE_FMT_S16P){
+        if(   av_get_bytes_per_sample(s-> in_sample_fmt) <= 2
+           && av_get_bytes_per_sample(s->out_sample_fmt) <= 2){
             s->int_sample_fmt= AV_SAMPLE_FMT_S16P;
-        }else if(   av_get_planar_sample_fmt(s-> in_sample_fmt) <= AV_SAMPLE_FMT_S16P
+        }else if(   av_get_bytes_per_sample(s-> in_sample_fmt) <= 2
            && !s->rematrix
            && s->out_sample_rate==s->in_sample_rate
            && !(s->flags & SWR_FLAG_RESAMPLE)){
@@ -226,7 +226,7 @@ av_cold int swr_init(struct SwrContext *s){
                  && !s->rematrix
                  && s->engine != SWR_ENGINE_SOXR){
             s->int_sample_fmt= AV_SAMPLE_FMT_S32P;
-        }else if(av_get_planar_sample_fmt(s->in_sample_fmt) <= AV_SAMPLE_FMT_FLTP){
+        }else if(av_get_bytes_per_sample(s->in_sample_fmt) <= 4){
             s->int_sample_fmt= AV_SAMPLE_FMT_FLTP;
         }else{
             s->int_sample_fmt= AV_SAMPLE_FMT_DBLP;