fs/resctrl: Optimize code in rdt_get_tree()

schemata_list_destroy() has to be called if schemata_list_create() fails.

rdt_get_tree() calls schemata_list_destroy() in two different ways:
directly if schemata_list_create() itself fails and
on the exit path via the out_schemata_free goto label.

Remove schemata_list_destroy() call on schemata_list_create() failure.
Use existing out_schemata_free goto label instead.

Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Koba Ko <kobak@nvidia.com>
Link: https://lore.kernel.org/20250623075051.3610592-1-tan.shaopeng@jp.fujitsu.com