Permit adjusting of advertisement data

Prior to this change subsequent calls to
QLowEnergyController::startAdvertising() failed to update the
to-be-advertised information.

Fixes: QTBUG-70754
Change-Id: I594f4f916307e12be6be17d50497aea324520620
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

src/bluetooth/qleadvertiser_p.h

@@ -73,13 +73,14 @@ public:
 signals:
     void errorOccurred();
 
-protected:
+public:
     QLeAdvertiser(const QLowEnergyAdvertisingParameters &params,
                   const QLowEnergyAdvertisingData &advData,
                   const QLowEnergyAdvertisingData &responseData, QObject *parent)
         : QObject(parent), m_params(params), m_advData(advData), m_responseData(responseData) {}
     virtual ~QLeAdvertiser() { }
 
+protected:
     const QLowEnergyAdvertisingParameters &parameters() const { return m_params; }
     const QLowEnergyAdvertisingData &advertisingData() const { return m_advData; }
     const QLowEnergyAdvertisingData &scanResponseData() const { return m_responseData; }
@@ -106,7 +107,7 @@ public:
                        const QLowEnergyAdvertisingData &advertisingData,
                        const QLowEnergyAdvertisingData &scanResponseData, HciManager &hciManager,
                        QObject *parent = nullptr);
-    ~QLeAdvertiserBluez();
+    ~QLeAdvertiserBluez() override;
 
 private:
     void doStartAdvertising() override;

src/bluetooth/qlowenergycontroller_bluez.cpp

@@ -810,8 +810,11 @@ void QLowEnergyControllerPrivateBluez::resetController()
 
     if (role == QLowEnergyController::PeripheralRole) {
         // public API behavior requires stop of advertisement
-        if (advertiser)
+        if (advertiser) {
             advertiser->stopAdvertising();
+            delete advertiser;
+            advertiser = nullptr;
+        }
         localAttributes.clear();
     }
 }