Fix test failure of node with no memory
Fix test failure of node with no memory

The HTools assume that Nodes have strictly more memory than the
Instance placed there, which 'setInstanceSmallerThanNode' doesn't
ensure.

Signed-off-by: Aaron Karper <99cc1031546340b2b8ced5fe338b5890677a56ca@google.com>
Reviewed-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>

yiannist/ganeti,bitemyapp/ganeti,leshchevds/ganeti,yiannist/ganeti,mbakke/ganeti,onponomarev/ganeti,andir/ganeti,andir/ganeti,bitemyapp/ganeti,ganeti/ganeti,grnet/snf-ganeti,leshchevds/ganeti,dimara/ganeti,mbakke/ganeti,yiannist/ganeti,ganeti/ganeti,leshchevds/ganeti,dimara/ganeti,ganeti/ganeti,andir/ganeti,mbakke/ganeti,grnet/snf-ganeti,onponomarev/ganeti