KVM: arm64: vgic: Undo work in failed ITS restores

Failed ITS restores should clean up all state restored until the
failure. There is some cleanup already present when failing to restore
some tables, but it's not complete. Add the missing cleanup.

Note that this changes the behavior in case of a failed restore of the
device tables.

	restore ioctl:
	1. restore collection tables
	2. restore device tables

With this commit, failures in 2. clean up everything created so far,
including state created by 1.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220510001633.552496-5-ricarkol@google.com