improve javadocs for numRamDocs

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@672290 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/lucene/index/IndexWriter.java

@@ -3416,9 +3416,8 @@ public class IndexWriter {
     return docWriter.getRAMUsed();
   }
 
-  /** Expert:  Return the number of documents whose segments are currently cached in memory.
-   * Useful when calling flush()
-   */
+  /** Expert:  Return the number of documents currently
+   *  buffered in RAM. */
   public final synchronized int numRamDocs() {
     ensureOpen();
     return docWriter.getNumDocsInRAM();