cloud: fix %v in cases where we should use %w

Change-Id: I161fe87fbc2bf8c4c2c7756074fc1050f268121e
Reviewed-on: https://review.monogon.dev/c/monogon/+/3099
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/cloud/shepherd/manager/initializer.go b/cloud/shepherd/manager/initializer.go
index a380a8f..1961fe2 100644
--- a/cloud/shepherd/manager/initializer.go
+++ b/cloud/shepherd/manager/initializer.go
@@ -169,7 +169,7 @@
 func (i *Initializer) processMachine(ctx context.Context, t *task) error {
 	machine, err := i.p.GetMachine(ctx, shepherd.ProviderID(t.machine.ProviderID))
 	if err != nil {
-		return fmt.Errorf("while fetching machine %q: %v", t.machine.ProviderID, err)
+		return fmt.Errorf("while fetching machine %q: %w", t.machine.ProviderID, err)
 	}
 
 	// Start the agent.