FREED LOCK

ANALYIS
-------

In 5.5 code the lock_rec_block_validate() is called after releasing
the kernel mutex. There is a chance that the lock might be invalid so,
we are getting the valgrind error on invalid read on lock->index.

FIX
---

Fix would be to copy the lock->index when we are holding the kernel mutex 
and then pass it to the lock_rec_block_validate(). This implementation
is present in 5.1 code.  

[ Approved by sunny rb.no.oracle.com/rb/r/2152/ ]