ntfs: fix sysctl table registration and path

ntfs: fix sysctl table registration and path

The presence of a sentinel (an empty {}) at the end of the ctl_table array
now causes a "sysctl table check failed" error because the kernel attempts
to validate the null entry as a functional node.
Deleted the empty {} from the ntfs_sysctls array to prevent
the "procname is null" and "No proc_handler" errors and updated the base
path from "fs" to "fs/ntfs" to ensure the ntfs-debug node is correctly
located under /proc/sys/fs/ntfs/.

Reported-by: Woody Suwalski <terraluna977@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>