[incfs] Use new IncFs_ReleaseControlFds() instead of duping

Vold needs to pass / accept IncFs control via Binder, so it
neeeds to get and put its internal FDs in and out. Using the new
release() function it works without extra fd duping

Bug: 153704006
Test: builds & boots
Change-Id: I64bc5b1ca9f2c69e34c3a860ed3edbe58bd9ea29
1 file changed