Fix JavaDoc typo in XContentBuilder (#1739)

Signed-off-by: Fabio Buso <buso.fabio@gmail.com>

libs/x-content/src/main/java/org/opensearch/common/xcontent/XContentBuilder.java

@@ -81,7 +81,7 @@ public final class XContentBuilder implements Closeable, Flushable {
      * The builder uses an internal {@link ByteArrayOutputStream} output stream to build the content. When both exclusive and
      * inclusive filters are provided, the underlying builder will first use exclusion filters to remove fields and then will check the
      * remaining fields against the inclusive filters.
-     * <p>
+     * </p>
      *
      * @param xContent the {@link XContent}
      * @param includes the inclusive filters: only fields and objects that match the inclusive filters will be written to the output.