tools/target_dec_fuzzer: Also fuzz request_channel_layout

This should improve coverage
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

tools/target_dec_fuzzer.c

@@ -210,6 +210,7 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
         ctx->block_align                        = bytestream2_get_le32(&gbc);
         ctx->codec_tag                          = bytestream2_get_le32(&gbc);
         keyframes                               = bytestream2_get_le64(&gbc);
+        ctx->request_channel_layout             = bytestream2_get_le64(&gbc);
 
         if (extradata_size < size) {
             ctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);