Do not set allocation_interval in allocator benchmark test.
Do not set allocation_interval in allocator benchmark test.

We already using `Clock::pause();` to manually drive the allocations,
so here we can remove the logic of set allocation_interval here.

Review: https://reviews.apache.org/r/50678/

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