smsc95xx: fix error checking of usbnet_resume

without this patch the two lines below won't ever execute

Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index e083f53..e8465fe 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -1304,7 +1304,7 @@
 		check_warn_return(ret, "Error writing PM_CTRL");
 	}
 
-	return usbnet_resume(intf);
+	ret = usbnet_resume(intf);
 	check_warn_return(ret, "usbnet_resume error");
 
 	return 0;