ACPICA: debugger: check status of acpi_evaluate_object() in acpi_db_walk_for_fields()

ACPICA commit 9061cd9aa131205657c811a52a9f8325a040c6c9

Errors in acpi_evaluate_object() can lead to incorrect state of buffer.

This can lead to access to data in previously ACPI_FREEd buffer and
secondary ACPI_FREE to the same buffer later.

Handle errors in acpi_evaluate_object the same way it is done earlier
with acpi_ns_handle_to_pathname.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Link: https://github.com/acpica/acpica/commit/9061cd9a
Fixes: 5fd03328

 ("ACPICA: debugger: add command to dump all fields of particular subtype")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>