LU-2675 libcfs: remove LUSTRE_{,SRV_}LNET_PID

LU-2675 libcfs: remove LUSTRE_{,SRV_}LNET_PID

Remove LUSTRE_LNET_PID (12354) and LUSTRE_SRV_LNET_PID (12345) from
the libcfs headers and replace their uses with a new macro
LNET_PID_LUSTRE (also 12345) in lnet/types.h.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Ib92e1eaa8237c998d04ee0110907dac2dbffdc5e
Reviewed-on: http://review.whamcloud.com/11985
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>