osbase/logtree.LeveledLogger -> go/logging.Leveled

This factors out the common leveled logger interface out of the logtree.
We want to use the same interface outside of logtree/supervisor usage
within the resolver code, which will be exposed to clients.

Change-Id: I299e76d91e8cefddf8f36f1e58432418c4694df2
Reviewed-on: https://review.monogon.dev/c/monogon/+/3411
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/node/core/update/update.go b/metropolis/node/core/update/update.go
index 7c9e1c3..2e30d2a 100644
--- a/metropolis/node/core/update/update.go
+++ b/metropolis/node/core/update/update.go
@@ -23,13 +23,13 @@
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/proto"
 
+	"source.monogon.dev/go/logging"
 	abloaderpb "source.monogon.dev/metropolis/node/core/abloader/spec"
 	"source.monogon.dev/osbase/blockdev"
 	"source.monogon.dev/osbase/build/mkimage/osimage"
 	"source.monogon.dev/osbase/efivarfs"
 	"source.monogon.dev/osbase/gpt"
 	"source.monogon.dev/osbase/kexec"
-	"source.monogon.dev/osbase/logtree"
 )
 
 // Service contains data and functionality to perform A/B updates on a
@@ -43,7 +43,7 @@
 	ESPPartNumber uint32
 
 	// Logger service for the update service.
-	Logger logtree.LeveledLogger
+	Logger logging.Leveled
 }
 
 type Slot int