netlabel: Mark rcu pointers with __rcu.

This fixes sparse errors of the form:
  incompatible types in comparison expression (different address spaces)

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c
index ada6742..d4d6640 100644
--- a/net/netlabel/netlabel_domainhash.c
+++ b/net/netlabel/netlabel_domainhash.c
@@ -55,8 +55,8 @@
 static DEFINE_SPINLOCK(netlbl_domhsh_lock);
 #define netlbl_domhsh_rcu_deref(p) \
 	rcu_dereference_check(p, lockdep_is_held(&netlbl_domhsh_lock))
-static struct netlbl_domhsh_tbl *netlbl_domhsh;
-static struct netlbl_dom_map *netlbl_domhsh_def;
+static struct netlbl_domhsh_tbl __rcu *netlbl_domhsh;
+static struct netlbl_dom_map __rcu *netlbl_domhsh_def;
 
 /*
  * Domain Hash Table Helper Functions