__init_page_from_nid() no longer has external users and is only used
locally in mm/mm_init.c under CONFIG_DEFERRED_STRUCT_PAGE_INIT.

Fold it into its sole caller __init_deferred_page() and remove the
separate helper declaration.

Signed-off-by: Muchun Song <redacted>
---
v2->v3:
- fold __init_page_from_nid() into __init_deferred_page() since it
  only has a single caller (suggested by Mike Rapoport)
---
 mm/internal.h |  1 -
 mm/mm_init.c  | 44 ++++++++++++++++++--------------------------
 2 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index 8497673d0ac3..b33fc87e4555 100644
--- a/mm/internal.h
+++ b/mm/internal.h

@@ -1760,7 +1760,6 @@ static inline bool pte_needs_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte
 
 void __meminit __init_single_page(struct page *page, unsigned long pfn,
 				unsigned long zone, int nid);
-void __meminit __init_page_from_nid(unsigned long pfn, int nid);
 
 /* shrinker related functions */
 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 41b83dd18c01..f1bbf3b9a321 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c

@@ -688,31 +688,6 @@ static __meminit void pageblock_migratetype_init_range(unsigned long pfn,
 }
 #endif
 
-/*
- * Initialize a reserved page unconditionally, finding its zone first.
- */
-void __meminit __init_page_from_nid(unsigned long pfn, int nid)
-{
-	pg_data_t *pgdat;
-	int zid;
-
-	pgdat = NODE_DATA(nid);
-
-	for (zid = 0; zid < MAX_NR_ZONES; zid++) {
-		struct zone *zone = &pgdat->node_zones[zid];
-
-		if (zone_spans_pfn(zone, pfn))
-			break;
-	}
-	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
-
-	if (pageblock_aligned(pfn)) {
-		enum migratetype mt =
-			kho_scratch_migratetype(pfn, MIGRATE_MOVABLE);
-		init_pageblock_migratetype(pfn_to_page(pfn), mt, false);
-	}
-}
-
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
 {

@@ -771,10 +746,27 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
 
 static void __meminit __init_deferred_page(unsigned long pfn, int nid)
 {
+	pg_data_t *pgdat;
+	int zid;
+
 	if (early_page_initialised(pfn, nid))
 		return;
 
-	__init_page_from_nid(pfn, nid);
+	pgdat = NODE_DATA(nid);