VM: make zap_page_range() return void

... since all callers ignore its return value and it's been
useless since commit 97a89413
(mm: Remove i_mmap_lock lockbreak) anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/mm.h

@@ -893,7 +893,7 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 
 int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size);
-unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
+void zap_page_range(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size, struct zap_details *);
 unsigned long unmap_vmas(struct mmu_gather *tlb,
 		struct vm_area_struct *start_vma, unsigned long start_addr,

mm/memory.c

@@ -1386,7 +1386,7 @@ unsigned long unmap_vmas(struct mmu_gather *tlb,
  * @size: number of bytes to zap
  * @details: details of nonlinear truncation or shared cache invalidation
  */
-unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
+void zap_page_range(struct vm_area_struct *vma, unsigned long address,
 		unsigned long size, struct zap_details *details)
 {
 	struct mm_struct *mm = vma->vm_mm;
@@ -1397,9 +1397,8 @@ unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
 	lru_add_drain();
 	tlb_gather_mmu(&tlb, mm, 0);
 	update_hiwater_rss(mm);
-	end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
+	unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
 	tlb_finish_mmu(&tlb, address, end);
-	return end;
 }
 
 /**