avfilter/af_silenceremove: remove dead code

Fixes CID1237284
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/af_silenceremove.c

@@ -335,13 +335,10 @@ silence_copy:
                                 flush(out, outlink, &nb_samples_written, &ret);
                                 goto silence_trim;
                             }
-                        } else {
-                            s->mode = SILENCE_COPY_FLUSH;
-                            flush(out, outlink, &nb_samples_written, &ret);
-                            goto silence_copy_flush;
                         }
+                        s->mode = SILENCE_COPY_FLUSH;
                         flush(out, outlink, &nb_samples_written, &ret);
-                        break;
+                        goto silence_copy_flush;
                     }
                 }
             }