af_unix: netns: fix problem of return value

fix problem of return value

net/unix/af_unix.c: unix_net_init()
when error appears, it should return 'error', not always return 0.
Signed-off-by: NJianjun Kong <jianjun@zeuux.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/unix/af_unix.c

@@ -2213,7 +2213,7 @@ static int unix_net_init(struct net *net)
 #endif
 	error = 0;
 out:
-	return 0;
+	return error;
 }
 
 static void unix_net_exit(struct net *net)