mm: fix prototype warning from kernel test robot

Patch series "mm: clean up names and parameters of memmap_init_xxxx functions", v5.

This patchset corrects inappropriate function names of memmap_init_xxx,
and simplify parameters of functions in the code flow.  And also fix a
prototype warning reported by lkp.

This patch (of 5);

Kernel test robot calling make with 'W=1' is triggering warning like
below for memmap_init_zone() function.

  mm/page_alloc.c:6259:23: warning: no previous prototype for 'memmap_init_zone' [-Wmissing-prototypes]
   6259 | void __meminit __weak memmap_init_zone(unsigned long size, int nid,
        |                       ^~~~~~~~~~~~~~~~

Fix it by adding the function declaration in include/linux/mm.h.  Since
memmap_init_zone() has a generic version with '__weak', the declaratoin in
ia64 header file can be simply removed.

Link: https://lkml.kernel.org/r/20210122135956.5946-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20210122135956.5946-2-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/ia64/include/asm/pgtable.h

@@ -517,12 +517,6 @@ extern struct page *zero_page_memmap_ptr;
 	__changed;							\
 })
 #endif
-
-#  ifdef CONFIG_VIRTUAL_MEM_MAP
-  /* arch mem_map init routine is needed due to holes in a virtual mem_map */
-    extern void memmap_init (unsigned long size, int nid, unsigned long zone,
-			     unsigned long start_pfn);
-#  endif /* CONFIG_VIRTUAL_MEM_MAP */
 # endif /* !__ASSEMBLY__ */
 
 /*

include/linux/mm.h

@@ -2408,6 +2408,8 @@ extern void set_dma_reserve(unsigned long new_dma_reserve);
 extern void memmap_init_zone(unsigned long, int, unsigned long,
 		unsigned long, unsigned long, enum meminit_context,
 		struct vmem_altmap *, int migratetype);
+extern void memmap_init(unsigned long size, int nid,
+		unsigned long zone, unsigned long range_start_pfn);
 extern void setup_per_zone_wmarks(void);
 extern int __meminit init_per_zone_wmark_min(void);
 extern void mem_init(void);