sbp_targ memory leak

[Sean Bruno]

In trying to understand and make sbp_targ functional, I've noted that 
the code seems to lose track of how many page tables it allocates for 
any give orbi.  I had to add a lot of debugging code around the 
malloc/free's to find out what was going on, and I'm not sure what the 
code is supposed to do in this case.

Please review the patch diff at --> http://consultcsg.com/RELENG_6.diff

And the log at -->http://consultcsg.com/malloc_failure.txt

This clearly shows that a new page table is being allocated for the same 
IO operation, which should be fine, but then a second malloc is 
attempted and stored in the same variable effectively leaking the data.  
I'm sure that this type of operation is supposed to be possible, but my 
interpretation of SBP-2 is suspect!  :)

Sean