alerting: fix a bunch of lint issues. (#17128)

pkg/services/alerting/eval_handler.go

@@ -9,11 +9,13 @@ import (
 	"github.com/grafana/grafana/pkg/infra/metrics"
 )
 
+// DefaultEvalHandler is responsible for evaluating the alert rule.
 type DefaultEvalHandler struct {
 	log             log.Logger
 	alertJobTimeout time.Duration
 }
 
+// NewEvalHandler is the `DefaultEvalHandler` constructor.
 func NewEvalHandler() *DefaultEvalHandler {
 	return &DefaultEvalHandler{
 		log:             log.New("alerting.evalHandler"),
@@ -21,6 +23,7 @@ func NewEvalHandler() *DefaultEvalHandler {
 	}
 }
 
+// Eval evaluated the alert rule.
 func (e *DefaultEvalHandler) Eval(context *EvalContext) {
 	firing := true
 	noDataFound := true