[t:4456], fix bad merge in ydb.c

git-svn-id: file:///svn/toku/tokudb@39580 c7de825b-a66e-492c-adef-691d508d4ae1

src/ydb.c

@@ -4433,10 +4433,10 @@ toku_db_cursor(DB * db, DB_TXN * txn, DBC ** c, u_int32_t flags, int is_temporar
             );
     }
 
-    //r = toku_grab_read_lock_on_directory(db, txn);
-    //if (r != 0) 
-    //    return r;
-    r = 0;
+    r = toku_grab_read_lock_on_directory(db, txn);
+    if (r != 0) 
+        return r;
+    
     struct __toku_dbc_external *XMALLOC(eresult); // so the internal stuff is stuck on the end
     memset(eresult, 0, sizeof(*eresult));
     DBC *result = &eresult->external_part;