mm, memory_hotplug: remove obsolete generic_free_nodedata()

Commit 390511e147 ("mm, memory_hotplug: drop arch_free_nodedata") drops
the last caller of generic_free_nodedata().  Remove it too.

Link: https://lkml.kernel.org/r/20220916072257.9639-11-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/memory_hotplug.h

@@ -43,11 +43,6 @@ extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
 ({								\
 	memblock_alloc(sizeof(*pgdat), SMP_CACHE_BYTES);	\
 })
-/*
- * This definition is just for error path in node hotadd.
- * For node hotremove, we have to replace this.
- */
-#define generic_free_nodedata(pgdat)	kfree(pgdat)
 
 extern pg_data_t *node_data[];
 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
@@ -63,9 +58,6 @@ static inline pg_data_t *generic_alloc_nodedata(int nid)
 	BUG();
 	return NULL;
 }
-static inline void generic_free_nodedata(pg_data_t *pgdat)
-{
-}
 static inline void arch_refresh_nodedata(int nid, pg_data_t *pgdat)
 {
 }