disable random exceptions on open where we open a reader and do checks (it will be reset next time thru the loop)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1466888 13f79535-47bb-0310-9956-ffa450edef68

lucene/core/src/test/org/apache/lucene/index/TestIndexWriterOnDiskFull.java

@@ -365,6 +365,7 @@ public class TestIndexWriterOnDiskFull extends LuceneTestCase {
           // we succeeded, we see all docs added, and if we
           // failed, we see either all docs or no docs added
           // (transactional semantics):
+          dir.setRandomIOExceptionRateOnOpen(0.0);
           try {
             reader = DirectoryReader.open(dir);
           } catch (IOException e) {