treewide: replace error comparisons and assertions with errors.Is

Change-Id: Id2424eb155f2c6842c72c5fafd124d428ef901f2
Reviewed-on: https://review.monogon.dev/c/monogon/+/2994
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/cloud/bmaas/scruffy/server.go b/cloud/bmaas/scruffy/server.go
index 58e0f51..01d22bf 100644
--- a/cloud/bmaas/scruffy/server.go
+++ b/cloud/bmaas/scruffy/server.go
@@ -9,6 +9,7 @@
 
 import (
 	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -77,7 +78,7 @@
 	go hwr.run(ctx)
 
 	go func() {
-		if err := s.Config.Webug.Start(ctx, conn); err != nil && err != ctx.Err() {
+		if err := s.Config.Webug.Start(ctx, conn); err != nil && !errors.Is(err, ctx.Err()) {
 			klog.Exitf("Failed to start webug: %v", err)
 		}
 	}()