PCI: endpoint: Populate func_no before calling pci_epc_add_epf()

func_no is a member of struct pci_epf.

Since struct pci_epf is used as an argument to pci_epc_add_epf() (to
bind an endpoint function to a controller), struct pci_epf.func_no
should be populated before calling pci_epc_add_epf().

Initialize the struct pci_epf.func_no member before calling
pci_epc_add_epf(), to fix the endpoint function binding to
an endpoint controller.

Fixes: d74679911610 ("PCI: endpoint: Introduce configfs entry for configuring EP functions")
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
[lorenzo.pieralisi@arm.com: rewrote the commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Suggested-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/pci/endpoint/pci-ep-cfs.c

@@ -97,22 +97,20 @@ static int pci_epc_epf_link(struct config_item *epc_item,
 {
 	int ret;
 	u32 func_no = 0;
-	struct pci_epc *epc;
-	struct pci_epf *epf;
 	struct pci_epf_group *epf_group = to_pci_epf_group(epf_item);
 	struct pci_epc_group *epc_group = to_pci_epc_group(epc_item);
-
-	epc = epc_group->epc;
-	epf = epf_group->epf;
-	ret = pci_epc_add_epf(epc, epf);
-	if (ret)
-		goto err_add_epf;
+	struct pci_epc *epc = epc_group->epc;
+	struct pci_epf *epf = epf_group->epf;
 
 	func_no = find_first_zero_bit(&epc_group->function_num_map,
 				      sizeof(epc_group->function_num_map));
 	set_bit(func_no, &epc_group->function_num_map);
 	epf->func_no = func_no;
 
+	ret = pci_epc_add_epf(epc, epf);
+	if (ret)
+		goto err_add_epf;
+
 	ret = pci_epf_bind(epf);
 	if (ret)
 		goto err_epf_bind;