Revert "avcodec/libopusenc: Fix warning when encoding ambisonics with channel mapping 2"

This reverts commit 4cd6f08d.

libavcodec/libopusenc.c

@@ -27,7 +27,6 @@
 #include "bytestream.h"
 #include "internal.h"
 #include "libopus.h"
-#include "mathops.h"
 #include "vorbis.h"
 #include "audio_frame_queue.h"
 
@@ -201,21 +200,6 @@ static int libopus_check_vorbis_layout(AVCodecContext *avctx, int mapping_family
     return 0;
 }
 
-static int libopus_check_ambisonics_channels(AVCodecContext *avctx) {
-    int channels = avctx->channels;
-    int ambisonic_order = ff_sqrt(channels) - 1;
-    if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)) &&
-        channels != ((ambisonic_order + 1) * (ambisonic_order + 1) + 2)) {
-        av_log(avctx, AV_LOG_ERROR,
-               "Ambisonics coding is only specified for channel counts"
-               " which can be written as (n + 1)^2 or (n + 1)^2 + 2"
-               " for nonnegative integer n\n");
-        return AVERROR_INVALIDDATA;
-    }
-
-    return 0;
-}
-
 static int libopus_validate_layout_and_get_channel_map(
         AVCodecContext *avctx,
         int mapping_family,
@@ -247,12 +231,6 @@ static int libopus_validate_layout_and_get_channel_map(
             channel_map = ff_vorbis_channel_layout_offsets[avctx->channels - 1];
         }
         break;
-    case 2:
-        ret = libopus_check_max_channels(avctx, 227);
-        if (ret == 0) {
-            ret = libopus_check_ambisonics_channels(avctx);
-        }
-        break;
     case 255:
         ret = libopus_check_max_channels(avctx, 254);
         break;