[AF_UNIX] Initialise UNIX sockets before general device initcalls

When drivers call request_module(), it tries to do something with UNIX
sockets and triggers a 'runaway loop modprobe net-pf-1' warning. Avoid
this by initialising AF_UNIX support earlier.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/unix/af_unix.c

@@ -2193,7 +2193,11 @@ static void __exit af_unix_exit(void)
 	unregister_pernet_subsys(&unix_net_ops);
 }
 
-module_init(af_unix_init);
+/* Earlier than device_initcall() so that other drivers invoking
+   request_module() don't end up in a loop when modprobe tries
+   to use a UNIX socket. But later than subsys_initcall() because
+   we depend on stuff initialised there */
+fs_initcall(af_unix_init);
 module_exit(af_unix_exit);
 
 MODULE_LICENSE("GPL");