avfilter/af_headphone: Fix leak of channel layouts list on error

In case the multichannel HRIR mode was enabled, an error could happen
between allocating a channel layouts list and attaching it to its target
destination. If an error happened, the list would leak. This is fixed by
attaching the list to its target directly after its allocation.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

libavfilter/af_headphone.c

@@ -703,6 +703,9 @@ static int query_formats(AVFilterContext *ctx)
         return ret;
 
     ret = ff_add_channel_layout(&stereo_layout, AV_CH_LAYOUT_STEREO);
+    if (ret)
+        return ret;
+    ret = ff_channel_layouts_ref(stereo_layout, &ctx->outputs[0]->in_channel_layouts);
     if (ret)
         return ret;
 
@@ -721,10 +724,6 @@ static int query_formats(AVFilterContext *ctx)
         }
     }
 
-    ret = ff_channel_layouts_ref(stereo_layout, &ctx->outputs[0]->in_channel_layouts);
-    if (ret)
-        return ret;
-
     formats = ff_all_samplerates();
     if (!formats)
         return AVERROR(ENOMEM);