Fixed a compilation issue on gcc 4.4.7.
Fixed a compilation issue on gcc 4.4.7.

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