PhotoVideoControl.qml: fix storage usage logic

The _mavlinkCameraStorageSupported currently tests that

    _mavlinkCamera.storageStatus === QGCCameraControl.STORAGE_NOT_SUPPORTED

Which is the opposite of what the name of the property suggests.

Two uses of the property expect that it does what it says, while one
use expects what it actually does.

This changes the test to make the property actually mean what it says
and fixes the use that requires the opposite case.

src/FlightMap/Widgets/PhotoVideoControl.qml

@@ -70,9 +70,9 @@ Rectangle {
     property bool   _mavlinkCameraPhotoCaptureIsIdle:           _mavlinkCamera && (_mavlinkCamera.photoStatus === QGCCameraControl.PHOTO_CAPTURE_IDLE || _mavlinkCamera.photoStatus >= QGCCameraControl.PHOTO_CAPTURE_LAST)
     property bool   _mavlinkCameraStorageReady:                 _mavlinkCamera && _mavlinkCamera.storageStatus === QGCCameraControl.STORAGE_READY
     property bool   _mavlinkCameraBatteryReady:                 _mavlinkCamera && _mavlinkCamera.batteryRemaining >= 0
-    property bool   _mavlinkCameraStorageSupported:             _mavlinkCamera && _mavlinkCamera.storageStatus === QGCCameraControl.STORAGE_NOT_SUPPORTED
+    property bool   _mavlinkCameraStorageSupported:             _mavlinkCamera && _mavlinkCamera.storageStatus !== QGCCameraControl.STORAGE_NOT_SUPPORTED
     property bool   _mavlinkCameraAllowsPhotoWhileRecording:    false
-    property bool   _mavlinkCameraCanShoot:                     (!_mavlinkCameraModeUndefined && ((_mavlinkCameraStorageReady && _mavlinkCamera.storageFree > 0) || _mavlinkCameraStorageSupported)) || _videoStreamManager.streaming
+    property bool   _mavlinkCameraCanShoot:                     (!_mavlinkCameraModeUndefined && ((_mavlinkCameraStorageReady && _mavlinkCamera.storageFree > 0) || !_mavlinkCameraStorageSupported)) || _videoStreamManager.streaming
     property bool   _mavlinkCameraIsShooting:                   ((_mavlinkCameraInVideoMode && _mavlinkCameraVideoIsRecording) || (_mavlinkCameraInPhotoMode && !_mavlinkCameraPhotoCaptureIsIdle)) || _videoStreamManager.recording
 
     // The following settings and functions unify between a mavlink camera and a simple video stream for simple access