net: nfs: Fix CVE-2022-30767 (old CVE-2019-14196)

net: nfs: Fix CVE-2022-30767 (old CVE-2019-14196)

This patch mitigates the vulnerability identified via CVE-2019-14196.

The previous patch was bypassed/ineffective, and now the vulnerability
is identified via CVE-2022-30767. The patch removes the sanity check
introduced to mitigate CVE-2019-14196 since it's ineffective.
filefh3_length is changed to unsigned type integer, preventing negative
numbers from being used during comparison with positive values during
size sanity checks.

Signed-off-by: Andrea zi0Black Cappa <zi0Black@protonmail.com>
Reviewed-By: Daniel Leidert <dleidert@debian.org>
Origin: https://source.denx.de/u-boot/u-boot/-/commit/bdbf7a05e26f3c5fd437c99e2755ffde186ddc80
Bug: https://lists.denx.de/pipermail/u-boot/2022-May/483952.htmll
Bug-Debian: https://bugs.debian.org/1014471
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2022-30767
Bug-Freexian-Security: https://deb.freexian.com/extended-lts/tracker/CVE-2022-30767

Gbp-Pq: Name CVE-2022-30767.patch