include/linux/nodemask.h: define next_memory_node() if !CONFIG_NUMA

Currently next_memory_node only exists when CONFIG_NUMA=y. This patch
adds the macro for !CONFIG_NUMA.

Signed-off-by: Yu Zhao <yuzhao@google.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>

include/linux/nodemask.h

@@ -486,6 +486,7 @@ static inline int num_node_state(enum node_states state)
 #define first_online_node	0
 #define first_memory_node	0
 #define next_online_node(nid)	(MAX_NUMNODES)
+#define next_memory_node(nid)	(MAX_NUMNODES)
 #define nr_node_ids		1U
 #define nr_online_nodes		1U