PCI/AER: Convert aer_get_device_error_info(), aer_print_error() to index

PCI/AER: Convert aer_get_device_error_info(), aer_print_error() to index

Previously aer_get_device_error_info() and aer_print_error() took a pointer
to struct aer_err_info and a pointer to a pci_dev.  Typically the pci_dev
was one of the elements of the aer_err_info.dev[] array (DPC was an
exception, where the dev[] array was unused).

Convert aer_get_device_error_info() and aer_print_error() to take an index
into the aer_err_info.dev[] array instead.  A future patch will add
per-device ratelimit information, so the index makes it convenient to find
the ratelimit associated with the device.

To accommodate DPC, set info->dev[0] to the DPC port before using these
interfaces.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/20250522232339.1525671-17-helgaas@kernel.org