windows: Fix memory leak in adapter.Scan (#383)

* Properly release acquired resources in getScanResultFromArgs * Simplify code

Author: MrMati

gap_windows.go

@@ -224,25 +224,33 @@ func getScanResultFromArgs(args *advertisement.BluetoothLEAdvertisementReceivedE
 Address: adr,
 }
 
+winAdv, err := args.GetAdvertisement()
+if err != nil {
+return result
+}
+defer winAdv.Release()
+
 var manufacturerData []ManufacturerDataElement
-if winAdv, err := args.GetAdvertisement(); err == nil && winAdv != nil {
-vector, _ := winAdv.GetManufacturerData()
-size, _ := vector.GetSize()
-for i := uint32(0); i < size; i++ {
-element, _ := vector.GetAt(i)
+mVector, _ := winAdv.GetManufacturerData()
+if mVector != nil {
+defer mVector.Release()
+mSize, _ := mVector.GetSize()
+for i := uint32(0); i < mSize; i++ {
+element, _ := mVector.GetAt(i)
 manData := (*advertisement.BluetoothLEManufacturerData)(element)
 companyID, _ := manData.GetCompanyId()
 buffer, _ := manData.GetData()
 manufacturerData = append(manufacturerData, ManufacturerDataElement{
 CompanyID: companyID,
 Data: bufferToSlice(buffer),
 })
+buffer.Release()
+manData.Release()
 }
 }
 
 // Note: the IsRandom bit is never set.
-advertisement, _ := args.GetAdvertisement()
-localName, _ := advertisement.GetLocalName()
+localName, _ := winAdv.GetLocalName()
 result.AdvertisementPayload = &advertisementFields{
 AdvertisementFields{
 LocalName: localName,