Allow NULL data in mount(2)
Allow NULL data in mount(2)

PiperOrigin-RevId: 213315267
Change-Id: I7562bcd81fb22e90aa9c7dd9eeb94803fcb8c5af

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor