PCI: hv: update comment in x86 specific hv_arch_irq_unmask

The function hv_set_affinity was removed in commit 831c1ae7 ("PCI: hv:
Make the code arch neutral by adding arch specific interfaces").

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Link: https://lore.kernel.org/r/20221107171831.25283-1-olaf@aepfle.de


Signed-off-by: Wei Liu <wei.liu@kernel.org>