LU-5030 libcfs: create cfs_get_paths() function

LU-5030 libcfs: create cfs_get_paths() function

With the move of the upstream client to sysfs the
lustre and lnet utilites no long should directly
access the proc file system. To avoid this a new
function is created to support both the traditional
procfs lustre/lnet parameters as well as the new
sysfs lustre/lnet parameters as well. Besides the
creation of these functions the LNet utilites are
converted to use these new functions.

Change-Id: I78788f41955073e1e48126103ef2aec13d64812b
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Signed-off-by: Wang Chao <chao.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/17459
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Ryan Haasken <haasken@cray.com>
Reviewed-by: Emoly Liu <emoly.liu@intel.com>