Catch attempts to use of acpi_driver_data on pointers of wrong type.

akpm: rewritten to use proper C typechecking and remove the
"function"-used-as-lvalue thing.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLen Brown <len.brown@intel.com>