powerpc/xive: Fix refcount leak in xive_spapr_init

powerpc/xive: Fix refcount leak in xive_spapr_init

BugLink: https://bugs.launchpad.net/bugs/1981864
[ Upstream commit 1d1fb9618bdd5a5fbf9a9eb75133da301d33721c ]

of_find_compatible_node() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
Add missing of_node_put() to avoid refcount leak.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220512090535.33397-1-linmq006@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>