KVM: arm64: vgic: Force vcpu vgic teardown on vcpu destroy

KVM: arm64: vgic: Force vcpu vgic teardown on vcpu destroy

When failing to create a vcpu because (for example) it has a
duplicate vcpu_id, we destroy the vcpu. Amusingly, this leaves
the redistributor registered with the KVM_MMIO bus.

This is no good, and we should properly clean the mess. Force
a teardown of the vgic vcpu interface, including the RD device
before returning to the caller.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231207151201.3028710-4-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>