sock_diag: fix autoloading of the raw_diag module

IPPROTO_RAW isn't registred as an inet protocol, so
inet_protos[protocol] is always NULL for it.

Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Xin Long <lucien.xin@gmail.com>
Fixes: bf2ae2e4 ("sock_diag: request _diag module only when the family or proto has been registered")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/sock.c

@@ -3279,6 +3279,7 @@ int sock_load_diag_module(int family, int protocol)
 
 #ifdef CONFIG_INET
 	if (family == AF_INET &&
+	    protocol != IPPROTO_RAW &&
 	    !rcu_access_pointer(inet_protos[protocol]))
 		return -ENOENT;
 #endif