refactor(pkg): rename plugin status constants

pkg/plugin/plugin.go

@@ -26,7 +26,7 @@ type Plugin struct {
 func New(name string) *Plugin {
 	p := new(Plugin)
 	p.name = name
-	p.status = UNKNOWN
+	p.status = StatusUnknown
 	p.message = "no status set"
 	p.perfData = make(map[string]*perfdata.PerfData)
 	return p

pkg/plugin/status.go

@@ -7,10 +7,10 @@ type Status int
 
 // Plugin exit statuses.
 const (
-	OK Status = iota
-	WARNING
-	CRITICAL
-	UNKNOWN
+	StatusOK Status = iota
+	StatusWarning
+	StatusCritical
+	StatusUnknown
 )
 
 // String representations of the plugin statuses.