[rust_cli] Consume result

In the last change we started calling the "show_command_hint" function,
but missed to consume it's result.

Change-Id: Icbbe52494db088c12d7cf77f8d179dfd9472c8a7
Signed-off-by: gtema <artem.goncharov@gmail.com>

codegenerator/templates/rust_cli/impl.rs.j2

@@ -267,7 +267,7 @@ impl {{ target_class_name }}Command {
 
 {%- endif %} {#- specialities #}
         // Show command specific hints
-        op.show_command_hint();
+        op.show_command_hint()?;
         Ok(())
     }
 }

codegenerator/tests/unit/test_rust_cli.py

@@ -114,7 +114,7 @@ impl fooCommand {
           let data = ep.query_async(client).await?;
           op.output_single::<rsp>(data)?;
         // Show command specific hints
-        op.show_command_hint();
+        op.show_command_hint()?;
         Ok(())
     }
 }