avfilter/af_afftdn: Assert format

Maybe helps: CID1515514 Uninitialized scalar variable
Maybe helps: CID1515517 Uninitialized scalar variable

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 8f9a6c4ea8)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavfilter/af_afftdn.c

@@ -20,6 +20,7 @@
 
 #include <float.h>
 
+#include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/opt.h"
@@ -375,6 +376,8 @@ static void process_frame(AVFilterContext *ctx,
         case AV_SAMPLE_FMT_DBLP:
             noisy_data[i] = mag = hypot(fft_data_dbl[i].re, fft_data_dbl[i].im);
             break;
+        default:
+            av_assert2(0);
         }
 
         power = mag * mag;
@@ -969,6 +972,8 @@ static void sample_noise_block(AudioFFTDeNoiseContext *s,
             mag2 = fft_out_dbl[n].re * fft_out_dbl[n].re +
                    fft_out_dbl[n].im * fft_out_dbl[n].im;
             break;
+        default:
+            av_assert2(0);
         }
 
         mag2 = fmax(mag2, s->sample_floor);