tests: compiling error
tests: compiling error

Function "av_free_packet" deprecated and suggest using "av_packet_unref"
in the new version of ffmpeg.

ffmpeg: b38e685c053786bc20743cc6b3e54e6ae1fe957b

YuJiankang/libyami,YuJiankang/libyami,uartie/libyami,andyLiuChina/libyami,halleyzhao/libyami,zhaobob/libyami,andyLiuChina/libyami,dspmeng/libyami,YuJiankang/libyami,dspmeng/libyami,yizhouwei/libyami,BtbN/libyami,seanvk/libyami,halleyzhao/libyami,BtbN/libyami,uartie/libyami,andyLiuChina/libyami,lizhong1008/libyami,halleyzhao/libyami,zhaobob/libyami,dspmeng/libyami,seanvk/libyami,chivakker/libyami,BtbN/libyami,BtbN/libyami,lizhong1008/libyami,yizhouwei/libyami,chivakker/libyami,lizhong1008/libyami,stripes416/libyami,clearlylin/libyami,uartie/libyami,zhaobob/libyami,yizhouwei/libyami,01org/libyami,stripes416/libyami,clearlylin/libyami,seanvk/libyami,clearlylin/libyami,01org/libyami,halleyzhao/libyami,stripes416/libyami,01org/libyami,chivakker/libyami,andyLiuChina/libyami