docs: correct plugin warning

docs/docs/advanced/plugins.md

@@ -205,7 +205,7 @@ $ trivy image --format json --output plugin=<plugin_name> [--output-plugin-arg <
 Since scan results are passed to the plugin via standard input, plugins must be capable of handling standard input.
 
 !!! warning
-    To avoid Trivy hanging, you need to read all data from `Stdin` before the plugin exits successfully or stops with an error code.
+    To avoid Trivy hanging, you need to read all data from `Stdin` before the plugin exits successfully or stops with an error.
 
 While the example passes JSON to the plugin, other formats like SBOM can also be passed (e.g., `--format cyclonedx`).