PCI/MSI: Correct misleading comments

stable inclusion
from linux-4.19.205
commit c5b223cd04706589e5e6840e2ab7c4f879323ed9

--------------------------------

commit 689e6b53 upstream.

The comments about preserving the cached state in pci_msi[x]_shutdown() are
misleading as the MSI descriptors are freed right after those functions
return. So there is nothing to restore. Preparatory change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210729222542.621609423@linutronix.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>