ALSA: usb-audio: Replace probing flag with active refcount

We can use active refcount for preventing autopm during probe.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/card.c b/sound/usb/card.c
index b6621bc..73c5833 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -371,7 +371,7 @@
 	chip->card = card;
 	chip->setup = device_setup[idx];
 	chip->autoclock = autoclock;
-	chip->probing = 1;
+	atomic_set(&chip->active, 1); /* avoid autopm during probing */
 	atomic_set(&chip->usage_count, 0);
 	atomic_set(&chip->shutdown, 0);
 
@@ -503,7 +503,7 @@
 				goto __error;
 			}
 			chip = usb_chip[i];
-			chip->probing = 1;
+			atomic_inc(&chip->active); /* avoid autopm */
 			break;
 		}
 	}
@@ -563,8 +563,8 @@
 
 	usb_chip[chip->index] = chip;
 	chip->num_interfaces++;
-	chip->probing = 0;
 	usb_set_intfdata(intf, chip);
+	atomic_dec(&chip->active);
 	mutex_unlock(&register_mutex);
 	return 0;
 
@@ -572,7 +572,7 @@
 	if (chip) {
 		if (!chip->num_interfaces)
 			snd_card_free(chip->card);
-		chip->probing = 0;
+		atomic_dec(&chip->active);
 	}
 	mutex_unlock(&register_mutex);
 	return err;
@@ -668,8 +668,6 @@
 {
 	if (atomic_read(&chip->shutdown))
 		return -EIO;
-	if (chip->probing)
-		return 0;
 	if (atomic_inc_return(&chip->active) == 1)
 		return usb_autopm_get_interface(chip->pm_intf);
 	return 0;
@@ -677,8 +675,6 @@
 
 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 {
-	if (chip->probing)
-		return;
 	if (atomic_dec_and_test(&chip->active))
 		usb_autopm_put_interface(chip->pm_intf);
 }