Return master ip script output in case of failure
Return master ip script output in case of failure

Currently only the exit code is returned, which is somewhat pointless:
for failures, we already know it's ≠ 0, so we don't have enough
information (reported on the mailing list). By logging the output as
well (if any), the user will have more information available for
debugging.

Signed-off-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>
Reviewed-by: Guido Trotter <f62ca4d5358bdaeef0e50e57f9f7e231de63727e@google.com>

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