Fixup service file for centos7
Fixup service file for centos7

Summary: Change the name of the binary, so update the service file

Differential Revision: D4062726

fbshipit-source-id: 3f68e723c100cafbda70c40c00df732acd01c758

peterlei/fboss,peterlei/fboss,peterlei/fboss,peterlei/fboss