SMB3: Fix mkdir when idsfromsid configured on mount

mkdir uses a compounded create operation which was not setting
the security descriptor on create of a directory. Fix so
mkdir now sets the mode and owner info properly when idsfromsid
and modefromsid are configured on the mount.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org> # v5.8
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>