ACPI: APEI: Better fix to avoid spamming the console with old error logs

The fix in commit 3f8dec11 ("ACPI/APEI: Limit printable size of BERT
table data") does not work as intended on systems where the BIOS has a
fixed size block of memory for the BERT table, relying on s/w to quit
when it finds a record with estatus->block_status == 0. On these systems
all errors are suppressed because the check:

	if (region_len < ACPI_BERT_PRINT_MAX_LEN)

always fails.

New scheme skips individual CPER records that are too large, and also
limits the total number of records that will be printed to 5.

Fixes: 3f8dec11

 ("ACPI/APEI: Limit printable size of BERT table data")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>