PCI: cpqphp: Fix possible null pointer dereference

There is otherwise a risk of a null pointer dereference.

Found by cppcheck, a static code analysis program.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/hotplug/cpqphp_ctrl.c b/drivers/pci/hotplug/cpqphp_ctrl.c
index 11845b7..f593585 100644
--- a/drivers/pci/hotplug/cpqphp_ctrl.c
+++ b/drivers/pci/hotplug/cpqphp_ctrl.c
@@ -709,7 +709,8 @@
 				temp = temp->next;
 			}
 
-			temp->next = max->next;
+			if (temp)
+				temp->next = max->next;
 		}
 
 		max->next = NULL;