LU-15930 lnet: Remove duplicate checks for peer sensitivity

LU-15930 lnet: Remove duplicate checks for peer sensitivity

Callers of lnet_inc_lpni_healthv_locked() and
lnet_dec_healthv_locked() currently check whether the parent peer
has a peer specific sensitivity defined. To remove this code
duplication, this logic is rolled into
lnet_inc_lpni_healthv_locked() and lnet_dec_lpni_healthv_locked().
The latter is a new wrapper around lnet_dec_healthv_locked().

lnet_dec_healthv_locked() is changed to return a bool indicating
whether the health value was actually modified so that the peer
net health is only updated when the peer NI health actually changes.

Test-Parameters: trivial testlist=sanity-lnet
HPE-bug-id: LUS-11018
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I624561167392ad625ea7478689e9c5975cec3f2e
Reviewed-on: https://review.whamcloud.com/46626
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>