adm8211: fix error return code

Return a negative error code on failure.

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

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/adm8211.c

@@ -1837,6 +1837,7 @@ static int adm8211_probe(struct pci_dev *pdev,
 	if (!priv->map) {
 		printk(KERN_ERR "%s (adm8211): Cannot map device memory\n",
 		       pci_name(pdev));
+		err = -ENOMEM;
 		goto err_free_dev;
 	}