PCI/AER: Use list_first_entry_or_null() to simplify code

Use list_first_entry_or_null() instead of list_empty() + list_entry() to
simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
1 file changed