staging/lustre/socklnd: remove ksnd_sysctl

It is dead code because we defined CFS_SYSFS_MODULE_PARM.

Cc: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>