audio: simplify audio_driver_init()

Catch and return from error early to avoid indentations and ease the
flow & return a bool for success value. All driver init() calls have
been checked to set errp on error.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

audio/audio.c

@@ -1562,35 +1562,27 @@ size_t audio_generic_read(HWVoiceIn *hw, void *buf, size_t size)
     return total;
 }
 
-static int audio_driver_init(AudioState *s, struct audio_driver *drv,
-                             Audiodev *dev, Error **errp)
+static bool audio_driver_init(AudioState *s, struct audio_driver *drv,
+                              Audiodev *dev, Error **errp)
 {
-    Error *local_err = NULL;
-
-    s->drv_opaque = drv->init(dev, &local_err);
-
-    if (s->drv_opaque) {
-        if (!drv->pcm_ops->get_buffer_in) {
-            drv->pcm_ops->get_buffer_in = audio_generic_get_buffer_in;
-            drv->pcm_ops->put_buffer_in = audio_generic_put_buffer_in;
-        }
-        if (!drv->pcm_ops->get_buffer_out) {
-            drv->pcm_ops->get_buffer_out = audio_generic_get_buffer_out;
-            drv->pcm_ops->put_buffer_out = audio_generic_put_buffer_out;
-        }
+    s->drv_opaque = drv->init(dev, errp);
+    if (!s->drv_opaque) {
+        return false;
+    }
 
-        audio_init_nb_voices_out(s, drv, 1);
-        audio_init_nb_voices_in(s, drv, 0);
-        s->drv = drv;
-        return 0;
-    } else {
-        if (local_err) {
-            error_propagate(errp, local_err);
-        } else {
-            error_setg(errp, "Could not init `%s' audio driver", drv->name);
-        }
-        return -1;
+    if (!drv->pcm_ops->get_buffer_in) {
+        drv->pcm_ops->get_buffer_in = audio_generic_get_buffer_in;
+        drv->pcm_ops->put_buffer_in = audio_generic_put_buffer_in;
     }
+    if (!drv->pcm_ops->get_buffer_out) {
+        drv->pcm_ops->get_buffer_out = audio_generic_get_buffer_out;
+        drv->pcm_ops->put_buffer_out = audio_generic_put_buffer_out;
+    }
+
+    audio_init_nb_voices_out(s, drv, 1);
+    audio_init_nb_voices_in(s, drv, 0);
+    s->drv = drv;
+    return true;
 }
 
 static void audio_vm_change_state_handler (void *opaque, bool running,
@@ -1748,7 +1740,7 @@ static AudioState *audio_init(Audiodev *dev, Error **errp)
         drvname = AudiodevDriver_str(dev->driver);
         driver = audio_driver_lookup(drvname);
         if (driver) {
-            done = !audio_driver_init(s, driver, dev, errp);
+            done = audio_driver_init(s, driver, dev, errp);
         } else {
             error_setg(errp, "Unknown audio driver `%s'", drvname);
         }
@@ -1768,7 +1760,7 @@ static AudioState *audio_init(Audiodev *dev, Error **errp)
             g_free(e);
             drvname = AudiodevDriver_str(dev->driver);
             driver = audio_driver_lookup(drvname);
-            if (!audio_driver_init(s, driver, dev, NULL)) {
+            if (audio_driver_init(s, driver, dev, NULL)) {
                 break;
             }
             qapi_free_Audiodev(dev);