af: fix behavior with pathologic filter chains

Some filter chains require a huge number of auto-inserted conversion
filters. There is an overly stupid safeguard against infinite filter
insertions, which counts the number of conversion filters inserted. This
triggered accidentally in this case. Fix by resetting this counter after
a non-conversion filter was successfully configured.

audio/filter/af.c

@@ -519,6 +519,8 @@ static int af_reinit(struct af_stream *s)
                    af->info->name, rv);
             goto error;
         }
+        if (af && !af->auto_inserted)
+            retry = 0;
     }
 
     /* Set previously unset fields in s->output to those of the filter chain