drivers/net/irda/sa1100_ir.c: fix error return code

The function sa1100_irda_probe() return 0 for success and negative
value for most of its internal tests failures. There is one exception
that is error case going to err_mem_4:. For this error case, the
function abort its success execution path, but returns non negative
value, making it difficult for a caller function to notice the error.

This patch fixes the error case that do not return negative value.

This was found by Coccinelle, but the code change was made by hand.
This patch is not robot generated.

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: David S. Miller <davem@davemloft.net>

drivers/net/irda/sa1100_ir.c

@@ -940,8 +940,10 @@ static int sa1100_irda_probe(struct platform_device *pdev)
 		goto err_mem_3;
 
 	dev = alloc_irdadev(sizeof(struct sa1100_irda));
-	if (!dev)
+	if (!dev) {
+		err = -ENOMEM;
 		goto err_mem_4;
+	}
 
 	SET_NETDEV_DEV(dev, &pdev->dev);