ALSA: rme9652: don't disable if not enabled

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: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Link: https://lore.kernel.org/r/20210321153840.378226-4-ztong0001@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>