net: enetc: add ratelimiting to VF mailbox error messages

net: enetc: add ratelimiting to VF mailbox error messages

Sashiko reported that a buggy or malicious guest VM can flood the host
kernel log by repeatedly sending VF-to-PF messages at a high rate,
degrading host performance and hiding important system logs [1].

Fix by replacing dev_err()/dev_warn() with dev_err_ratelimited(),
limiting output to the default kernel ratelimit. This ensures errors are
still logged for debugging while preventing log flooding attacks.

Link: https://sashiko.dev/#/patchset/20260511080805.2052495-1-wei.fang%40nxp.com
Fixes: beb74ac878c8 ("enetc: Add vf to pf messaging support")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Link: https://patch.msgid.link/20260520064421.91569-4-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>