ACPI PPTT: Fix coding mistakes in a couple of sizeof() calls

The end of table checks should be done with the structure size,
but 2 of the 3 similar calls use the pointer size.

Signed-off-by: Jean-Marc Eurin <jmeurin@google.com>
Link: https://patch.msgid.link/20250402001542.2600671-1-jmeurin@google.com


[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>