s3: smbd: Ensure init_smb1_request() zeros out what the incoming pointer points to.

s3: smbd: Ensure init_smb1_request() zeros out what the incoming pointer points to.

Remove the now unneeded req->xxx = NULL assignments (and the
deliberately bogus req->session = (void *)0xDEADBEEF one
used to demonstrate the bug).

Remove knownfail.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15432

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Noel Power <npower@samba.org>
Autobuild-User(master): Noel Power <npower@samba.org>
Autobuild-Date(master): Tue Aug 15 12:06:36 UTC 2023 on atb-devel-224