lib/util, lib/svcutil: Remove unused code (#7309)

Duplicates the definition in lib/svcutil.

Co-authored-by: greatroar <@>

lib/util/utils.go

@@ -250,20 +250,6 @@ func AddressUnspecifiedLess(a, b net.Addr) bool {
 	return aIsUnspecified
 }
 
-type ExitStatus int
-
-const (
-	ExitSuccess            ExitStatus = 0
-	ExitError              ExitStatus = 1
-	ExitNoUpgradeAvailable ExitStatus = 2
-	ExitRestart            ExitStatus = 3
-	ExitUpgrade            ExitStatus = 4
-)
-
-func (s ExitStatus) AsInt() int {
-	return int(s)
-}
-
 // OnDone calls fn when ctx is cancelled.
 func OnDone(ctx context.Context, fn func()) {
 	go func() {