Fix OS Diagnose in light of the new OS Search path (Part One).
Fix OS Diagnose in light of the new OS Search path (Part One).

As of now only the last OS was taken into consideration by diagnose, fix by
storing them all and displaying for now only the first. Also display the source
path for valid OSes.


Reviewed-by: imsnah



mbakke/ganeti,apyrgio/snf-ganeti,leshchevds/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,ganeti/ganeti,dimara/ganeti,mbakke/ganeti,mbakke/ganeti,bitemyapp/ganeti,ganeti-github-testing/ganeti-test-1,andir/ganeti,andir/ganeti,onponomarev/ganeti,grnet/snf-ganeti,yiannist/ganeti,onponomarev/ganeti,andir/ganeti,apyrgio/ganeti,dimara/ganeti,grnet/snf-ganeti,ganeti/ganeti,leshchevds/ganeti,leshchevds/ganeti,bitemyapp/ganeti,yiannist/ganeti,apyrgio/snf-ganeti,ganeti/ganeti,apyrgio/ganeti