[skip ci] Add comment for HandleCStatus (#9043)

Signed-off-by: bigsheeper <yihao.dai@zilliz.com>

internal/querynode/cgo_helper.go

@@ -62,6 +62,7 @@ func (protoCGo *ProtoCGo) destruct() {
 	protoCGo.blob = nil
 }
 
+// HandleCStatus deal with the error returned from CGO
 func HandleCStatus(status *C.CStatus, extraInfo string) error {
 	if status.error_code == 0 {
 		return nil