can: peak_pcmcia: fix error return code

Convert a nonnegative error return code to a negative one, as returned
elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/sja1000/peak_pcmcia.c

@@ -686,8 +686,10 @@ static int __devinit pcan_probe(struct pcmcia_device *pdev)
 
 	/* detect available channels */
 	pcan_add_channels(card);
-	if (!card->chan_count)
+	if (!card->chan_count) {
+		err = -ENOMEM;
 		goto probe_err_4;
+	}
 
 	/* init the timer which controls the leds */
 	init_timer(&card->led_timer);