fix qemu_alloc/qemu_free for audio subsystem

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>
diff --git a/audio/paaudio.c b/audio/paaudio.c
index ff43bdd..a50fccc 100644
--- a/audio/paaudio.c
+++ b/audio/paaudio.c
@@ -340,7 +340,7 @@
     return 0;
 
  fail3:
-    free (pa->pcm_buf);
+    qemu_free (pa->pcm_buf);
     pa->pcm_buf = NULL;
  fail2:
     pa_simple_free (pa->s);
@@ -394,7 +394,7 @@
     return 0;
 
  fail3:
-    free (pa->pcm_buf);
+    qemu_free (pa->pcm_buf);
     pa->pcm_buf = NULL;
  fail2:
     pa_simple_free (pa->s);