Use pointer based TLS field (#13659)

This will help other projects like `health-analyzer` to verify that the
struct was indeed populated by the minio server, and is not
default-populated during unmarshalling of the JSON.

Signed-off-by: Shireesh Anjal <shireesh@minio.io>

cmd/admin-handlers.go

@@ -1835,6 +1835,7 @@ func (a adminAPIHandlers) HealthInfoHandler(w http.ResponseWriter, r *http.Reque
 				})
 			}
 
+			tls := getTLSInfo()
 			healthInfo.Minio.Info = madmin.MinioInfo{
 				Mode:         infoMessage.Mode,
 				Domain:       infoMessage.Domain,
@@ -1847,7 +1848,7 @@ func (a adminAPIHandlers) HealthInfoHandler(w http.ResponseWriter, r *http.Reque
 				Services:     infoMessage.Services,
 				Backend:      infoMessage.Backend,
 				Servers:      servers,
-				TLS:          getTLSInfo(),
+				TLS:          &tls,
 			}
 			partialWrite(healthInfo)
 		}