core/pci: Fix mem-leak on fast-reboot

Fast-reboot has a memory leak which causes the system to crash after about
250 fast-reboots. The patch fixes the memory leak.
The cause of the leak was the pci_device's being freed, without freeing
the pci_slot within it.

Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

core/pci.c

@@ -1641,6 +1641,7 @@ static void __pci_reset(struct list_head *list)
 	while ((pd = list_pop(list, struct pci_device, link)) != NULL) {
 		__pci_reset(&pd->children);
 		dt_free(pd->dn);
+		free(pd->slot);
 		free(pd);
 	}
 }