Remove nullability of operation on FBiOSTargetOperation
Remove nullability of operation on FBiOSTargetOperation

Summary: This was only ever used in fbsimctl and there are no examples of nullability being a problem here.

Reviewed By: zeyadsalloum

Differential Revision: D25461077

fbshipit-source-id: e5b9720570c9a50d9f997fe5bb501ccfdd9891d9

facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl,facebook/FBSimulatorControl