arm64/numa: avoid inconsistent information to be printed

numa_init may return error because of numa configuration error. So "No
NUMA configuration found" is inaccurate. In fact, specific configuration
error information should be immediately printed by the testing branch.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>