zebra: zrouter.in_shutdown is an atomic variable

So let's treat the variable like it is atomic and
properly load it when we need to look at it.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

zebra/zebra_mpls.c

@@ -1035,15 +1035,12 @@ static void lsp_processq_del(struct work_queue *wq, void *data)
 	struct zebra_lsp *lsp;
 	struct hash *lsp_table;
 	struct zebra_nhlfe *nhlfe;
-	bool in_shutdown = false;
 
 	/* If zebra is shutting down, don't delete any structs,
 	 * just ignore this callback. The LSPs will be cleaned up
 	 * during the shutdown processing.
 	 */
-	in_shutdown = atomic_load_explicit(&zrouter.in_shutdown,
-					   memory_order_relaxed);
-	if (in_shutdown)
+	if (zebra_router_in_shutdown())
 		return;
 
 	zvrf = vrf_info_lookup(VRF_DEFAULT);

zebra/zebra_nhg.c

@@ -1058,7 +1058,7 @@ static void zebra_nhg_set_invalid(struct nhg_hash_entry *nhe)
 	/* If we're in shutdown, this interface event needs to clean
 	 * up installed NHGs, so don't clear that flag directly.
 	 */
-	if (!zrouter.in_shutdown)
+	if (!zebra_router_in_shutdown())
 		UNSET_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED);
 
 	/* Update validity of nexthops depending on it */
@@ -1697,7 +1697,7 @@ void zebra_nhg_decrement_ref(struct nhg_hash_entry *nhe)
 
 	nhe->refcnt--;
 
-	if (!zrouter.in_shutdown && nhe->refcnt <= 0 &&
+	if (!zebra_router_in_shutdown() && nhe->refcnt <= 0 &&
 	    CHECK_FLAG(nhe->flags, NEXTHOP_GROUP_INSTALLED) &&
 	    !CHECK_FLAG(nhe->flags, NEXTHOP_GROUP_KEEP_AROUND)) {
 		nhe->refcnt = 1;

zebra/zebra_router.h

@@ -285,6 +285,11 @@ static inline void zebra_router_set_supports_nhgs(bool support)
 	zrouter.supports_nhgs = support;
 }
 
+static inline bool zebra_router_in_shutdown(void)
+{
+	return atomic_load_explicit(&zrouter.in_shutdown, memory_order_relaxed);
+}
+
 /* zebra_northbound.c */
 extern const struct frr_yang_module_info frr_zebra_info;