Revert "Copy virtual display FB to outbuf even with no app layers"

This reverts commit 2cacc353e699139eb7966576fe33f48e74c09e26.

Change-Id: Iba7e9acb8e1e8ae40e4b0b046adf9b16f57ced11
Signed-off-by: Ricardo Salveti de Araujo <ricardo.salveti@canonical.com>
Backport ubuntu's patch

https://code-review.phablet.ubuntu.com/gitweb?p=CyanogenMod/android_hardware_qcom_display.git;a=commit;h=d8049eb3563299f55d5941df33ef7a0dcff0c718
Change-Id: Ie4a9b8cf7136b15a37af924e371ccc7dcfb2fb0a