re #12611 rb4105 zpool import panic in ddt_zap_count()

@@ -19,10 +19,11 @@
  * CDDL HEADER END
  */
 
 /*
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  */
 
 #include <sys/zfs_context.h>
 #include <sys/spa.h>
 #include <sys/zio.h>

@@ -132,18 +133,17 @@
         }
         zap_cursor_fini(&zc);
         return (error);
 }
 
-static uint64_t
-ddt_zap_count(objset_t *os, uint64_t object)
+static int
+ddt_zap_count(objset_t *os, uint64_t object, uint64_t *count)
 {
-        uint64_t count = 0;
+        int error = zap_count(os, object, count);
+        ASSERT(error == 0);
 
-        VERIFY(zap_count(os, object, &count) == 0);
-
-        return (count);
+        return (error);
 }
 
 const ddt_ops_t ddt_zap_ops = {
         "zap",
         ddt_zap_create,