Fixed incorrect indent in `files.cpp`.
Fixed incorrect indent in `files.cpp`.

Review: https://reviews.apache.org/r/53394/

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