Made RepositoryItemUid #getLock and #getAttributeLock the same

Both DefaultRepositoryItemUid #getLock and #getAttributeLock lazy
initialized and returned the same DefaultRepositoryItemUid.lock
member. This means that both methods returned the same value for
any given itemUid instance. Most likely this was always item lock,
but the code is too convoluted to tell if any code paths used
attribute lock.

To guarantee consistent use of locks, made both #getLock and
and #getAttributeLock always return the same item lock.

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>

nexus/nexus-api/src/main/java/org/sonatype/nexus/proxy/item/DefaultRepositoryItemUid.java

@@ -86,16 +86,11 @@ public synchronized RepositoryItemUidLock getLock()
 
         return lock;
     }
-    
+
     @Override
     public synchronized RepositoryItemUidLock getAttributeLock()
     {
-        if ( lock == null )
-        {
-            lock = factory.createUidAttributeLock( this );
-        }
-
-        return lock;
+        return getLock();
     }
 
     @Override

nexus/nexus-api/src/main/java/org/sonatype/nexus/proxy/item/RepositoryItemUid.java

@@ -95,6 +95,8 @@ public interface RepositoryItemUid
      * As you can see on {@link RepositoryItemUidLock#unlock()} method javadoc, last of the boxed unlocks (if any boxing
      * at all, simply last invocation) also releases the lazily created lock.
      * 
+     * @deprecated this method is fully equivalent to {@link #getLock()}
+     * 
      * @return
      */
     RepositoryItemUidLock getAttributeLock();