cmd/mbf: optional init verbosity

This output is generally not needed and only useful when debugging container machinery itself.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/cache.go

@@ -21,6 +21,7 @@ type cache struct {
 
 	cures, jobs        int
 	hostAbstract, idle bool
+	verboseInit        bool
 
 	base string
 }
@@ -45,6 +46,9 @@ func (cache *cache) open() (err error) {
 	if cache.hostAbstract {
 		flags |= pkg.CHostAbstract
 	}
+	if !cache.verboseInit {
+		flags |= pkg.CSuppressInit
+	}
 
 	done := make(chan struct{})
 	defer close(done)