smb: client: delete "true", "false" defines

[ Upstream commit 5d390df3 ]

Kernel has its own official true/false definitions.

The defines aren't even used in this file.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>