libata: handle pci_enable_device() failure while resuming

Handle pci_enable_device() failure while resuming.  This patch kills
the "ignoring return value of 'pci_enable_device'" warning message and
propagates __must_check through ata_pci_device_do_resume().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 5aa288d..da982ed 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -1200,8 +1200,11 @@
 {
 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
 	struct sil24_host_priv *hpriv = host->private_data;
+	int rc;
 
-	ata_pci_device_do_resume(pdev);
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
 
 	if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND)
 		writel(HOST_CTRL_GLOBAL_RST, hpriv->host_base + HOST_CTRL);