mm/memory.c: mark functions as static

mark functions as static in memory.c because they are not used outside
this file.

This eliminates the following warnings in mm/memory.c:

  mm/memory.c:3530:5: warning: no previous prototype for `numa_migrate_prep' [-Wmissing-prototypes]
  mm/memory.c:3545:5: warning: no previous prototype for `do_numa_page' [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c

@@ -3531,7 +3531,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
 }
 
-int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
+static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
 				unsigned long addr, int page_nid,
 				int *flags)
 {
@@ -3546,7 +3546,7 @@ int numa_migrate_prep(struct page *page, struct vm_area_struct *vma,
 	return mpol_misplaced(page, vma, addr);
 }
 
-int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
+static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		   unsigned long addr, pte_t pte, pte_t *ptep, pmd_t *pmd)
 {
 	struct page *page = NULL;