[#1396] cli/playground: Refactor

Signed-off-by: Alexander Chuprov <a.chuprov@yadro.com>

cmd/frostfs-cli/modules/container/policy_playground.go

@@ -206,7 +206,7 @@ func (repl *policyPlaygroundREPL) run() error {
 		AutoComplete:    policyPlaygroundCompleter,
 	})
 	if err != nil {
-		fmt.Println("error initializing readline:", err)
+		return fmt.Errorf("error initializing readline: %w", err)
 	}
 	defer rl.Close()
 
@@ -221,7 +221,7 @@ func (repl *policyPlaygroundREPL) run() error {
 				exit = true
 				continue
 			}
-			return fmt.Errorf("reading line: %v", err)
+			return fmt.Errorf("reading line: %w", err)
 		}
 		exit = false