hwc2: Always store a release fence if a layer is presented

If the layer goes to GPU composition, there is no release fence
saved for it. When it comes back to SDE composition the fences
are no longer deferred. Fix this by always pushing a -1 release
fence for GPU composed layers.

Bug: 29642583
Change-Id: Ic8c46296133c119e7a2c4da2089fe7b37a03bd31
1 file changed