Reuse GetCloudTargetEnv in FormatAzureProdFQDN (#2376)
Reuse GetCloudTargetEnv in FormatAzureProdFQDN (#2376)

* reuse GetCloudTargetEnv in FormatAzureProdFQDN

* Fix FQDNFormat lint error

rjtsdl/acs-engine,rjtsdl/acs-engine,yangl900/acs-engine,jackfrancis/acs-engine,yangl900/acs-engine,yangl900/acs-engine,rjtsdl/acs-engine,rjtsdl/acs-engine,Azure/acs-engine,rjtsdl/acs-engine,yangl900/acs-engine,jackfrancis/acs-engine,jackfrancis/acs-engine,jackfrancis/acs-engine,Azure/acs-engine,Azure/acs-engine,Azure/acs-engine,jackfrancis/acs-engine,Azure/acs-engine,yangl900/acs-engine