Fix incorrect ConfigurationPropertyName javadoc

Author: philwebb

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/source/ConfigurationPropertyName.java

@@ -248,7 +248,7 @@ public ConfigurationPropertyName chop(int size) {
 
 	/**
 	 * Return a new {@link ConfigurationPropertyName} by based on this name offset by
-	 * specific element index. For example, {@code chop(1)} on the name {@code foo.bar}
+	 * specific element index. For example, {@code subName(1)} on the name {@code foo.bar}
 	 * will return {@code bar}.
 	 * @param offset the element offset
 	 * @return the sub name