LU-9120 lnet: add global health statistics

LU-9120 lnet: add global health statistics

Added global health statistics

Print that from lnetctl.

lnetctl stats show

lnet_selftest passes the statistics block over the wire. This,
unfortunately, creates an unnecessary backwards compatibility link
for lnet_selftest, which shouldn't be there. This patch breaks
this backwards compatibility, which means lnet_selftest will
not work with older selftest modules.

Test-Parameters: forbuildonly
Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Change-Id: I4a171c4f3cf13a1e8ab0d607d3b328352f727380
Reviewed-on: https://review.whamcloud.com/32949
Reviewed-by: Olaf Weber <olaf.weber@hpe.com>
Tested-by: Jenkins
Reviewed-by: Sonia Sharma <sharmaso@whamcloud.com>