[NET]: Avoid atomic xchg() for non-error case

It also looks like there were 2 places where the test on sk_err was
missing from the event wait logic (in sk_stream_wait_connect and
sk_stream_wait_memory), while the rest of the sock_error() users look
to be doing the right thing.  This version of the patch fixes those,
and cleans up a few places that were testing ->sk_err directly.

Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c
index 6f92f9c..f121f7d 100644
--- a/net/irda/af_irda.c
+++ b/net/irda/af_irda.c
@@ -1438,8 +1438,9 @@
 			/*
 			 *	POSIX 1003.1g mandates this order.
 			 */
-			if (sk->sk_err)
-				ret = sock_error(sk);
+			ret = sock_error(sk);
+			if (ret)
+				break;
 			else if (sk->sk_shutdown & RCV_SHUTDOWN)
 				;
 			else if (noblock)