PCI: pciehp: return error on read/write failure

Current pciehp returns successfully on read/write failure with dummy
state values. It should return error instead.

With this patch, pciehp no longer uses hotplug_slot_info data
structure. So this also removes hotplug_slot_info related code. But
note that it still allocates hotplug_slot_info because it is required
by pci hotplug core.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 88b654e..7f35aff 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -427,27 +427,24 @@
 	struct controller *ctrl = slot->ctrl;
 	u16 slot_cmd;
 	u16 cmd_mask;
-	int rc;
 
 	cmd_mask = PCI_EXP_SLTCTL_AIC;
 	switch (value) {
-		case 0 :	/* turn off */
-			slot_cmd = 0x00C0;
-			break;
-		case 1:		/* turn on */
-			slot_cmd = 0x0040;
-			break;
-		case 2:		/* turn blink */
-			slot_cmd = 0x0080;
-			break;
-		default:
-			return -1;
+	case 0 :	/* turn off */
+		slot_cmd = 0x00C0;
+		break;
+	case 1:		/* turn on */
+		slot_cmd = 0x0040;
+		break;
+	case 2:		/* turn blink */
+		slot_cmd = 0x0080;
+		break;
+	default:
+		return -EINVAL;
 	}
-	rc = pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n",
 		 __func__, ctrl->cap_base + PCI_EXP_SLTCTL, slot_cmd);
-
-	return rc;
+	return pcie_write_cmd(ctrl, slot_cmd, cmd_mask);
 }
 
 void pciehp_green_led_on(struct slot *slot)