#423 Invalid -net parameters fails silently

[Andreas Jacobsen]

An invalid line such as:
-net nic,vlan0,macaddr=00:00:10:52:37:48
will boot a KVM with a default macaddr for eth0 without errors and warnings, since it ignores everything after "vlan0".
-net nic,vlan=0,macaddr=00:00:10:52:37:48 works as it should.

Shouldn't KVM fail to start at all?