PCI: fix AER driver error information

Below patch fixes aer driver error information and enables aer driver
although CONFIG_ACPI=n.

As a matter of fact, the new patch is created from below 2 patches plus
a minor patch apply fuzz fixing. Because the second patch fixed a compilation
error introduced by the first patch, I merge them to facilitate bisect.

1) http://marc.info/?l=linux-kernel&m=117783233918191&w=2;
2) http://marc.info/?l=linux-mm-commits&m=118046936720790&w=2

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>