Problem:

In the clustered index, when an update operation is done the overall
scenario (after rb#4479) is as follows:

1.  Delete mark the old record that is to be updated.
2.  The old record disowns the blobs.
3.  Insert the new record into clustered index.
4.  For non-updated blobs, new record must own it. Verified by assert.
5.  For non-updated blobs, in new record marked as inherited.

Scenario involving DB_LOCK_WAIT:

If step 3 times out, then we will skip 1 and 2 and will continue from
step 3.  This skipping is achieved by the UPD_NODE_INSERT_BLOB state.
In this case, step 4 is not correct.  Because of step 1, the new
record need not own the blobs.  Hence the assert failure.

Solution:

The assert in step 4 is removed.  Instead code is added to ensure that
the record owns the blob.  

Note:

This is a regression caused by rb#4479.

rb#4571 approved by Marko