nfsd: Revert "nfsd: check for oversized NFSv2/v3 arguments"

This reverts commit 51f56777 "nfsd: check for oversized NFSv2/v3
arguments", which breaks support for NFSv3 ACLs.

That patch was actually an earlier draft of a fix for the problem that
was eventually fixed by e6838a29 "nfsd: check for oversized NFSv2/v3
arguments".  But somehow I accidentally left this earlier draft in the
branch that was part of my 2.12 pull request.

Reported-by: Eryu Guan <eguan@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>