LU-11300 lnet: router sensitivity

LU-11300 lnet: router sensitivity

Introduce the router_sensitivity_percentage module parameter to
control the sensitivity of routers to failures. It defaults to 100%
which means a router interface needs to be fully healthy in order
to be used.

Test-Parameters: forbuildonly
Signed-off-by: Amir Shehata <ashehata@whamcloud.com>
Change-Id: I3e9333033f049918c1cdca58a72604c71884acbe
Reviewed-on: https://review.whamcloud.com/33449
Tested-by: Jenkins
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Chris Horn <hornc@cray.com>