LU-11477 lnet: handle health for incoming messages

LU-11477 lnet: handle health for incoming messages

In case of routers (as well as for the general case) it's important to
update the health of the ni/lpni for incoming messages. For an lpni
specifically when we receive a message is when we know that the lpni
is up.

A percentage router health is required in order to send a message to a
gateway. That defaults to 100, meaning that a router interface has to
be absolutely healthy in order to send to it. This matches the current
behavior. So if a router interface goes down an its health goes down
significantly, but then it comes back up again; either we receive a
message from it or we discover it and get a reply, then in order to
start using that router interface again we have to boost its health
all the way up to maximum.

This behavior is special cased for routers.

Test-Parameters: forbuildonly
Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Change-Id: Ida6c23f95dbef56c2e6ed7b6d03743939d8b30a0
Reviewed-on: https://review.whamcloud.com/33301
Tested-by: Jenkins