libata: fix ata_eh_suspend() return value

ata_eh_suspend() was returning 0 regardless of failure.  This bug has
potential to lose data on suspend.  Fix it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 56cf59b..7484358 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1796,7 +1796,7 @@
 		*r_failed_dev = dev;
 
 	DPRINTK("EXIT\n");
-	return 0;
+	return rc;
 }
 
 /**