audio: replace vm_running with runstate_is_running()

AudioBackend had a vm_running field which was set in
audio_vm_change_state_handler().

The state change handler "bool running" argument is true when
vm_prepare_start() calls it, and the VM runstate is either SUSPENDED or
RUNNING.

Audio hw voices shouldn't be running when the VM is suspended, but only
when running. Thus replacing the vm_running field with a call to
runstate_is_running() is both simpler and more correct.

Reviewed-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

audio/audio.c

@@ -933,7 +933,7 @@ void AUD_set_active_out(SWVoiceOut *sw, bool on)
             hw->pending_disable = 0;
             if (!hw->enabled) {
                 hw->enabled = true;
-                if (s->vm_running) {
+                if (runstate_is_running()) {
                     if (hw->pcm_ops->enable_out) {
                         hw->pcm_ops->enable_out(hw, true);
                     }
@@ -979,7 +979,7 @@ void AUD_set_active_in(SWVoiceIn *sw, bool on)
         if (on) {
             if (!hw->enabled) {
                 hw->enabled = true;
-                if (s->vm_running) {
+                if (runstate_is_running()) {
                     if (hw->pcm_ops->enable_in) {
                         hw->pcm_ops->enable_in(hw, true);
                     }
@@ -1598,7 +1598,6 @@ static void audio_vm_change_state_handler (void *opaque, bool running,
     HWVoiceOut *hwo = NULL;
     HWVoiceIn *hwi = NULL;
 
-    s->vm_running = running;
     while ((hwo = audio_pcm_hw_find_any_enabled_out(s, hwo))) {
         if (hwo->pcm_ops->enable_out) {
             hwo->pcm_ops->enable_out(hwo, running);

audio/audio_int.h

@@ -252,7 +252,6 @@ typedef struct AudioBackend {
     QLIST_HEAD (cap_listhead, CaptureVoiceOut) cap_head;
     int nb_hw_voices_out;
     int nb_hw_voices_in;
-    int vm_running;
     int64_t period_ticks;
 
     bool timer_running;