staging/lustre/libcfs: Remove redundant lnet debugfs variables

/proc/sys/lnet/console_ratelimit, debug_path and panic_on_lbug
are module parameters with no special magic accessible via
/sys/module/libcfs/parameters/libcfs_console_ratelimit,
/sys/module/libcfs/parameters/libcfs_debug_file_path and
/sys/module/libcfs/parameters/libcfs_panic_on_lbug respectively.

As such just replace them with corresponding symlinks

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>