Use O_CREAT instead of NSData creation
Use O_CREAT instead of NSData creation

Summary: `open` supports this with options

Reviewed By: c-ryan747

Differential Revision: D15801820

fbshipit-source-id: c749def6eeab511c32b29d405f7090519e7fba35

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