cifs: fix the out of range assignment to bit fields in parse_server_interfaces

[ Upstream commit c9c9c6815f9004ee1ec87401ed0796853bd70f1b ]

Because the out of range assignment to bit fields
are compiler-dependant, the fields could have wrong
value.

Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>