Fix code snippets in Javadoc for exchangeSuccessfully()

Closes gh-35642

Signed-off-by: Dónal Murtagh <donal.murtagh@clarusonesourcing.com>

spring-test/src/main/java/org/springframework/test/web/reactive/server/WebTestClient.java

@@ -709,7 +709,7 @@ public interface WebTestClient {
 		 * Variant of {@link #exchange()} that expects a successful response.
 		 * Effectively, a shortcut for:
 		 * <pre class="code">
-		 * exchange().is2xxSuccessful()
+		 * exchange().expectStatus().is2xxSuccessful()
 		 * </pre>
 		 * @return a spec for expectations on the response
 		 * @since 7.0

spring-test/src/main/java/org/springframework/test/web/servlet/client/RestTestClient.java

@@ -523,7 +523,7 @@ public interface RestTestClient {
 		 * Variant of {@link #exchange()} that expects a successful response.
 		 * Effectively, a shortcut for:
 		 * <pre class="code">
-		 * exchange().is2xxSuccessful()
+		 * exchange().expectStatus().is2xxSuccessful()
 		 * </pre>
 		 * @return a spec for expectations on the response
 		 */