ALSA: sound/atmel/abdac.c: fix error return code

Initialize retval before returning from a failed call to ioremap.

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: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/atmel/abdac.c

@@ -452,6 +452,7 @@ static int __devinit atmel_abdac_probe(struct platform_device *pdev)
 	dac->regs = ioremap(regs->start, resource_size(regs));
 	if (!dac->regs) {
 		dev_dbg(&pdev->dev, "could not remap register memory\n");
+		retval = -ENOMEM;
 		goto out_free_card;
 	}