powerpc/eeh: Skip finding bus until after failure reporting

In eeh_handle_special_event(), eeh_pe_bus_get() is called before calling
eeh_report_failure() on every device under a PE.  If a PE was missing a
bus for some reason, the error would occur before reporting failure, even
though eeh_report_failure() doesn't require a bus.

Fix this by moving the bus retrieval and error check after the
eeh_report_failure() calls.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/eeh_driver.c

@@ -993,6 +993,8 @@ static void eeh_handle_special_event(void)
 
 				/* Notify all devices to be down */
 				eeh_pe_state_clear(pe, EEH_PE_PRI_BUS);
+				eeh_pe_dev_traverse(pe,
+					eeh_report_failure, NULL);
 				bus = eeh_pe_bus_get(phb_pe);
 				if (!bus) {
 					pr_err("%s: Cannot find PCI bus for "
@@ -1002,8 +1004,6 @@ static void eeh_handle_special_event(void)
 					       pe->addr);
 					break;
 				}
-				eeh_pe_dev_traverse(pe,
-					eeh_report_failure, NULL);
 				pci_hp_remove_devices(bus);
 			}
 			pci_unlock_rescan_remove();