Don't show flash icon if the device not supported it

[vsk-pvr]

java.lang.NullPointerException at devliving.online.mvbarcodereader.camera.CameraSource.setFlashMode(CameraSource.java:567) at devliving.online.mvbarcodereader.BarcodeCaptureFragment$1.onClick(BarcodeCaptureFragment.java:129) at android.view.View.performClick(View.java:4508) at android.view.View$PerformClick.run(View.java:18675) at android.os.Handler.handleCallback(Handler.java:733) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5590) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084) at dalvik.system.NativeStart.main(Native Method)