test: have `ExecuteContext` return result of `RunCommandContext` directly
test: have `ExecuteContext` return result of `RunCommandContext` directly

`RunCommandContext` will return if the context's `Done` channel is signaled, so
we don't need to check it again in callers of `RunCommandContext`.

Signed-off by: Ian Vernon <ian@cilium.io>

cilium/cilium,cilium/cilium,cilium-team/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium,cilium/cilium,tklauser/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,cilium-team/cilium,tgraf/cilium