PCI/DPC: Initialize aer_err_info before using it

Previously the struct aer_err_info "info" was allocated on the stack
without being initialized, so it contained junk except for the fields we
explicitly set later.

Initialize "info" at declaration so it starts as all zeros.

Fixes: 8aefa9b0 ("PCI/DPC: Print AER status in DPC event handling")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20250522232339.1525671-2-helgaas@kernel.org