crypto: rng - Ensure set_ent is always present

commit c0d36727bf39bb16ef0a67ed608e279535ebf0da upstream.

Ensure that set_ent is always set since only drbg provides it.

BUG=b/459128349
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2025-40109 in the Linux kernel.

cos-patch: security-moderate
Fixes: 77ebdabe8de7 ("crypto: af_alg - add extra parameters for DRBG interface")
Reported-by: Yiqi Sun <sunyiqixm@gmail.com>
Change-Id: I97211fa7c038c51638a9dd612c9480bb58aff9b4
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kernel CVE Triage Automation <cloud-image-kernel-cve-triage-automation@prod.google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/117641
Reviewed-by: Kevin Berry <kpberry@google.com>
Reviewed-by: Angel Adetula <angeladetula@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>