mm: unexport apply_to_existing_page_range

apply_to_existing_page_range() is only used by non-modular code.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/memory.c

···
 {
 	return __apply_to_page_range(mm, addr, size, fn, data, false);
 }
-EXPORT_SYMBOL_GPL(apply_to_existing_page_range);
 
 /*
  * handle_pte_fault chooses page fault handler according to an entry which was