smb: client: disable path remapping with POSIX extensions

If SMB 3.1.1 POSIX Extensions are available and negotiated, the client
should be able to use all characters and not remap anything. Currently, the
user has to explicitly request this behavior by specifying the "nomapposix"
mount option.

Link: https://lore.kernel.org/4195bb677b33d680e77549890a4f4dd3b474ceaf.camel@rx2.rx-server.de


Signed-off-by: Philipp Kerling <pkerling@casix.org>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>