VMAF builds do not compile

[Former user]

https://bitbucket.org/multicoreware/x265/commits/303ff9e4546d0052e7a4d359323f0aca84eedd68#Lsource/abrEncApp.cppT817

tries to access the member m_cliopt.argCount, but it doesn't exist, I assume it should be argCnt

Kevin