lib: parser: update documentation for match_NUMBER functions

commit 67222c4b ("lib: parser: optimize match_NUMBER apis to use local
array") removed -ENOMEM as a possible return value, so update the comments
accordingly.

Link: https://lkml.kernel.org/r/20230224042618.9092-1-ebiggers@kernel.org


Fixes: 67222c4b ("lib: parser: optimize match_NUMBER apis to use local array")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Cc: Li Lingfeng <lilingfeng3@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Yu Kuai <yukuai1@huaweicloud.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>