avfilter/af_ashowinfo: fix scaling factor of replaygain peak values

Commit 8542f9c4f1 changed replaygain peak
values to use 100k instead of UINT32_MAX as peak, with possibility of
overflow. af_ashowinfo was never updated to reflect this, so we update
it now.

Fixes: 8542f9c4f1
Signed-off-by: Kacper Michajłow <kasper93@gmail.com>

libavfilter/af_ashowinfo.c

@@ -120,7 +120,7 @@ static void print_peak(AVFilterContext *ctx, const char *str, uint32_t peak)
     if (!peak)
         av_log(ctx, AV_LOG_INFO, "unknown");
     else
-        av_log(ctx, AV_LOG_INFO, "%f", (float)peak / UINT32_MAX);
+        av_log(ctx, AV_LOG_INFO, "%f", peak / 100000.0f);
     av_log(ctx, AV_LOG_INFO, ", ");
 }