Fixed variable shadowing in `launchTaskPosix`.
Fixed variable shadowing in `launchTaskPosix`.

Review: https://reviews.apache.org/r/48836/

dforsyth/mesos,Gilbert88/mesos,Aman-Jain-14/customizedMesos,jpeach/mesos,gsantovena/mesos,abudnik/mesos,yuquanshan/customizedMesos,asamerh4/mesos,yuquanshan/customizedMesos,dforsyth/mesos,zmalik/mesos,chhsia0/mesos,yuquanshan/customizedMesos,abudnik/mesos,kaysoky/mesos,chhsia0/mesos,Gilbert88/mesos,verizonlabs/mesos,jpeach/mesos,reneploetz/mesos,kaysoky/mesos,zmalik/mesos,verizonlabs/mesos,chhsia0/mesos,gsantovena/mesos,abudnik/mesos,asamerh4/mesos,reneploetz/mesos,zmalik/mesos,craimbert/mesos,zmalik/mesos,andschwa/mesos,Aman-Jain-14/customizedMesos,andschwa/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,asamerh4/mesos,craimbert/mesos,andschwa/mesos,kaysoky/mesos,chhsia0/mesos,gsantovena/mesos,craimbert/mesos,Aman-Jain-14/customizedMesos,dforsyth/mesos,neilconway/mesos,jpeach/mesos,gsantovena/mesos,gsantovena/mesos,abudnik/mesos,zmalik/mesos,Aman-Jain-14/customizedMesos,kaysoky/mesos,kaysoky/mesos,jpeach/mesos,neilconway/mesos,reneploetz/mesos,verizonlabs/mesos,yuquanshan/customizedMesos,gsantovena/mesos,chhsia0/mesos,jpeach/mesos,kaysoky/mesos,Gilbert88/mesos,Gilbert88/mesos,asamerh4/mesos,Aman-Jain-14/customizedMesos,reneploetz/mesos,gsantovena/mesos,chhsia0/mesos,verizonlabs/mesos,andschwa/mesos,neilconway/mesos,dforsyth/mesos,yuquanshan/customizedMesos,jpeach/mesos,reneploetz/mesos,neilconway/mesos,reneploetz/mesos,Aman-Jain-14/customizedMesos,zmalik/mesos,andschwa/mesos,abudnik/mesos,asamerh4/mesos,zmalik/mesos,dforsyth/mesos,neilconway/mesos,jpeach/mesos,chhsia0/mesos,verizonlabs/mesos,neilconway/mesos,craimbert/mesos,neilconway/mesos,asamerh4/mesos,reneploetz/mesos,craimbert/mesos,craimbert/mesos,yuquanshan/customizedMesos,Gilbert88/mesos,andschwa/mesos,andschwa/mesos,craimbert/mesos,kaysoky/mesos,Gilbert88/mesos,yuquanshan/customizedMesos,verizonlabs/mesos,dforsyth/mesos,abudnik/mesos,asamerh4/mesos,Aman-Jain-14/customizedMesos,verizonlabs/mesos