treewide: replace always true switch condition with default

Change-Id: I6c2089f2499ab7d5dd55ad1a8d8a97e7276e171e
Reviewed-on: https://review.monogon.dev/c/monogon/+/2974
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/cloud/shepherd/manager/provisioner.go b/cloud/shepherd/manager/provisioner.go
index 63f74f4..db16ffa 100644
--- a/cloud/shepherd/manager/provisioner.go
+++ b/cloud/shepherd/manager/provisioner.go
@@ -108,7 +108,7 @@
 			klog.Errorf("Session expired, restarting...")
 			sess = nil
 			time.Sleep(time.Second)
-		case err != nil:
+		default:
 			klog.Errorf("Processing failed: %v", err)
 			// TODO(q3k): close session
 			time.Sleep(time.Second)