[IA64-SGI] Altix BTE error handling fixes

Altix (shub2) pushes the BTE clean-up into SAL.
This patch correctly interfaces with the now implemented SAL call.
It also fixes a bug when delaying clean-up to allow busy BTEs to
complete (or error out).

Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>