Bug#881045: fix build failure when building with -O3

[Matthias Klose]

Package: src:libyami
Version: 1.3.0-1
Tags: patch

There is a wrong warning when building with -O3, because -Werror is turned on by
default:

vaapiencoder_base.cpp: In member function ‘virtual YamiStatus
YamiMediaCodec::VaapiEncoderBase::getOutput(VideoEncOutputBuffer*, bool)’:
vaapiencoder_base.cpp:686:5: error: ‘isEmpty’ may be used uninitialized in this
function [-Werror=maybe-uninitialized]
     if (isEmpty)
     ^~
cc1plus: all warnings being treated as errors
Makefile:676: recipe for target 'libyami_encoder_la-vaapiencoder_base.lo' failed

work around at
http://launchpadlibrarian.net/344806674/libyami_1.3.0-1_1.3.0-1ubuntu1.diff.gz