Restore old value of buffer_size

This brings latency down to acceptable levels when using dmix

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4865 c046a42c-6fe2-441c-8c8c-71466251a162

audio/alsaaudio.c

@@ -58,6 +58,7 @@ static struct {
     int period_size_out_overridden;
     int verbose;
 } conf = {
+    .buffer_size_out = 1024,
     .pcm_name_out = "default",
     .pcm_name_in = "default",
 };