ksmbd: fix typo, syncronous->synchronous

syncronous->synchronous

Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>