ALSA: rme9652: don't disable if not enabled

rme9652 wants to disable a not enabled pci device, which makes kernel
throw a warning. Make sure the device is enabled before calling disable.

[    1.751595] snd_rme9652 0000:00:03.0: disabling already-disabled device
[    1.751605] WARNING: CPU: 0 PID: 174 at drivers/pci/pci.c:2146 pci_disable_device+0x91/0xb0
[    1.759968] Call Trace:
[    1.760145]  snd_rme9652_card_free+0x76/0xa0 [snd_rme9652]
[    1.760434]  release_card_device+0x4b/0x80 [snd]
[    1.760679]  device_release+0x3b/0xa0
[    1.760874]  kobject_put+0x94/0x1b0
[    1.761059]  put_device+0x13/0x20
[    1.761235]  snd_card_free+0x61/0x90 [snd]
[    1.761454]  snd_rme9652_probe+0x3be/0x700 [snd_rme9652]
Suggested-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NTong Zhang <ztong0001@gmail.com>
Link: https://lore.kernel.org/r/20210321153840.378226-4-ztong0001@gmail.comSigned-off-by: NTakashi Iwai <tiwai@suse.de>

sound/pci/rme9652/rme9652.c

@@ -1733,7 +1733,8 @@ static int snd_rme9652_free(struct snd_rme9652 *rme9652)
 	if (rme9652->port)
 		pci_release_regions(rme9652->pci);
 
-	pci_disable_device(rme9652->pci);
+	if (pci_is_enabled(rme9652->pci))
+		pci_disable_device(rme9652->pci);
 	return 0;
 }