Correct deprecation message for StringBuilder { }.

libraries/stdlib/src/kotlin/text/StringBuilder.kt

@@ -6,7 +6,7 @@ package kotlin
 /**
  * Builds newly created StringBuilder using provided body.
  */
-@Deprecated("Use StringBuilder().apply { body } or use String.build { body } if you need String as a result.", ReplaceWith("StringBuilder().apply(body)"))
+@Deprecated("Use StringBuilder().apply { body } or use buildString { body } if you need String as a result.", ReplaceWith("StringBuilder().apply(body)"))
 public inline fun StringBuilder(body: StringBuilder.() -> Unit): StringBuilder = StringBuilder().apply(body)
 
 /**