smb311: additional compression flag defined in updated protocol spec

[ Upstream commit e56bc745 ]

Added new compression flag that was recently documented, in
addition fix some typos and clarify the sid_attr_data struct
definition.

Reviewed-by: Bharath SM <bharathsm@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>