PROBLEM
-------

1) This is a regression caused by the patch for the bug fix
   Bug #28491099 [FATAL] MEMORY BLOCK IS INVALID | INNODB: ASSERTION FAILURE: UT0UT.CC:670

2) A pointer local to the function was storing the address of the blob_heap for
   a non partitioned table.The blob_heap is freed in case of normal table, but
   the address is still stored in local  pointer (it becomes a dangling pointer)
   which is then  assigned to the m_prebuilt. Since the memory associated with
   the address is already freed, it causes debug assertion while doing address
   validation.

FIX
---

1) Removed the local pointer which is used for reassigning, since it is
   not needed. The blob heaps address are stored seperatedly in
   ha_innopart::m_blob_heap_parts[]  array and freed in ha_innopart::clear_blob_heaps().

RB          : 23620
RB	    : 23684
Reviewed-by : Mayank Prasad <mayank.prasad@oracle.com>