Revert "Document HBOSS test cases known to fail under Null lock implementation"

This reverts commit 522ddafa13ec8936b72a45f102ca4a21e1a6b9a2.
diff --git a/hbase-oss/README.md b/hbase-oss/README.md
index 4755143..ec433d9 100644
--- a/hbase-oss/README.md
+++ b/hbase-oss/README.md
@@ -43,10 +43,6 @@
 The null implementation just provides no-op methods instead of actual locking
 operations. This functions as an easy way to verify that a test case has
 successfully reproduced a problem that is hidden by the other implementations.
-Notice this implementation should consistently fail tests enforcing atomicity,
-such as TestAtomicRename and TestCreateNonRecursive. Additional tests may
-eventually fail due to unpredictable race conditions, since no lock behaviour
-is being implemented.
 
 ### Local Implementation (org.apache.hadoop.hbase.oss.sync.LocalTreeLockManager)