powerpc/pseries: Add missing of_node_put() in ibmebus

In ibmebus_match_path(), use of_node_put() to drop the reference
returned by of_find_node_by_path() before testing for equality of the
pointers.

Signed-off-by: Liang He <windhl@126.com>
[mpe: Rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220619074016.4068105-1-windhl@126.com