pcie_aer: Convert pcie_aer_init to Error

When user specify invalid value for property aer_log_max, device should
fail to create, and report appropriate message.

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: Dmitry Fleytman <dmitry@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
