Fix a long-standing bug in local cache.  Since 20060317, the pointer to
next object is the first element in its common header.  Remove bogus
LinkOffset from ACPI_MEMORY_LIST and directly use NextObject.
Add macros to access pointer to next object in the descriptor list.
Add parens within macros around parameter names.
Regression fix: reinstate safe exit macros.

Removal caused a regression on at least FreeBSD. This fix reinstates
the macros.
Merge branch 'master' of ssh://ssh.github.com/juikim/acpica