iproute2 doesn't handle rto_min suffix settings correctly

Issue

• iproute2 seems to mishandle the value of the rto_min setting when the setting is suffixed by any measurement units, in our very case by 'ms'. It looks like the routing code expects millisecs buts gets jiffies - so there is a 6 orders of magnitude mismatch leading to unexpected behaviour. In our case instead of the wanted 1ms rto_min the code tried to set 1000 secs (!) and as the possible maximum is 120 secs rto_min was set to 2 mins.