soxr: fix output len too small

This was happening when the instant ratio was smaller than the fixed ratio
(when the user ask for a playback speed > 1).

Fixes issue 956 on vlc-android.

modules/audio_filter/resampler/soxr.c

@@ -312,7 +312,8 @@ Resample( filter_t *p_filter, block_t *p_in )
         block_t *p_flushed_out = NULL, *p_out = NULL;
         const double f_ratio = p_filter->fmt_out.audio.i_rate
                              / (double) p_filter->fmt_in.audio.i_rate;
-        const size_t i_olen = SoXR_GetOutLen( p_in->i_nb_samples, f_ratio );
+        size_t i_olen = SoXR_GetOutLen( p_in->i_nb_samples,
+            f_ratio > p_sys->f_fixed_ratio ? f_ratio : p_sys->f_fixed_ratio );
 
         if( f_ratio != p_sys->f_fixed_ratio )
         {