test: Return non-zero code if building tests fails
test: Return non-zero code if building tests fails

Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

cilium/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,michi-covalent/cilium,tklauser/cilium