LU-14654 lnet: Correct peer NI recovery age out calculation

LU-14654 lnet: Correct peer NI recovery age out calculation

The calculation to age a peer NI out of recovery is only valid if
lnet_recovery_limit is non-zero. When set to zero, we allow peer NIs
to be in recovery indefinitely.

Test-Parameters: trivial
HPE-bug-id: LUS-9953
Fixes: cc27201a76 ("LU-13569 lnet: Age peer NI out of recovery")
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I6bb40ca3a9affa0eaaae9deb1cecdb03e4bb42c5
Reviewed-on: https://review.whamcloud.com/43501
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>