Revert "hwc: Call MSMFB_DISPLAY_COMMIT even if FB handle is null."

This reverts commit 90e3ee8878feeb36a326ab032f2332d2612feb63.
Revert "gralloc:  Send first 2 FB buffers to carveout and next to IOMMU"

This reverts commit d80a52cbf961d737f6f3beef47b868a581b98591.
libgralloc: Report if numberOfBuffers was overritten