drivers/net/irda/irtty-sir.c: fix error return code

Author: Peter Senna Tschudin <peter.senna@gmail.com>

The function irtty_open() return 0 for success and negative value
for most of its internal tests failures. There is one exception
that is error case going to out_put:. 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/)

// 
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// 

Signed-off-by: Peter Senna Tschudin 
Signed-off-by: David S. Miller 

---
 drivers/net/irda/irtty-sir.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
 
diff --git a/drivers/net/irda/irtty-sir.c b/drivers/net/irda/irtty-sir.c
index 30087ca..6e4d4b6 100644
--- a/drivers/net/irda/irtty-sir.c
+++ b/drivers/net/irda/irtty-sir.c
@@ -459,8 +459,10 @@ static int irtty_open(struct tty_struct *tty)
 
 	/* allocate private device info block */
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-	if (!priv)
+	if (!priv) {
+		ret = -ENOMEM;
 		goto out_put;
+	}
 
 	priv->magic = IRTTY_MAGIC;
 	priv->tty = tty;