staging: winbond: use dev_err() instead of printk()

For obvious error messages, use dev_err() in order to provide userspace
with more useful information and use the common kernel coding style.
Signed-off-by: Martin Kepplinger <martink@posteo.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/winbond/wb35tx.c

@@ -49,7 +49,7 @@ static void Wb35Tx_complete(struct urb *pUrb)
 
 	/* The URB is completed, check the result */
 	if (pWb35Tx->EP4VM_status != 0) {
-		printk("URB submission failed\n");
+		dev_err(&pUrb->dev->dev, "URB submission failed\n");
 		pWb35Tx->EP4vm_state = VM_STOP;
 		goto error;
 	}
@@ -96,7 +96,7 @@ static void Wb35Tx(struct wbsoft_priv *adapter)
 	pWb35Tx->EP4vm_state = VM_RUNNING;
 	retv = usb_submit_urb(pUrb, GFP_ATOMIC);
 	if (retv < 0) {
-		printk("EP4 Tx Irp sending error\n");
+		dev_err(&pUrb->dev->dev, "EP4 Tx Irp sending error\n");
 		goto cleanup;
 	}
 
@@ -218,7 +218,7 @@ static void Wb35Tx_EP2VM_complete(struct urb *pUrb)
 
 	/* The Urb is completed, check the result */
 	if (pWb35Tx->EP2VM_status != 0) {
-		printk("EP2 IoCompleteRoutine return error\n");
+		dev_err(&pUrb->dev->dev, "EP2 IoCompleteRoutine return error\n");
 		pWb35Tx->EP2vm_state = VM_STOP;
 		goto error;
 	}