misc: small fix or general refactoring i did not bother commenting

modules/graph/dot.go

@@ -7,6 +7,9 @@ import (
 )
 
 func (mod *Module) generateDotGraph(bssid string) error {
+	mod.wLock.Lock()
+	defer mod.wLock.Unlock()
+
 	start := time.Now()
 	if err := mod.updateSettings(); err != nil {
 		return err

modules/graph/json.go

@@ -7,6 +7,9 @@ import (
 )
 
 func (mod *Module) generateJSONGraph(bssid string) error {
+	mod.wLock.Lock()
+	defer mod.wLock.Unlock()
+	
 	start := time.Now()
 	if err := mod.updateSettings(); err != nil {
 		return err

modules/graph/module.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"sync"
 	"time"
 )
 
@@ -46,6 +47,7 @@ type Module struct {
 	gw       *Node
 	iface    *Node
 	eventBus session.EventBus
+	wLock    sync.Mutex
 }
 
 func NewModule(s *session.Session) *Module {