um: remove vma linked list walk

Use the VMA iterator instead.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Alexandre Frade <kernel@xanmod.org>

arch/um/kernel/tlb.c

@@ -584,21 +584,19 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 
 void flush_tlb_mm(struct mm_struct *mm)
 {
-	struct vm_area_struct *vma = mm->mmap;
+	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
 
-	while (vma != NULL) {
+	for_each_vma(vmi, vma)
 		fix_range(mm, vma->vm_start, vma->vm_end, 0);
-		vma = vma->vm_next;
-	}
 }
 
 void force_flush_all(void)
 {
 	struct mm_struct *mm = current->mm;
-	struct vm_area_struct *vma = mm->mmap;
+	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
 
-	while (vma != NULL) {
+	for_each_vma(vmi, vma)
 		fix_range(mm, vma->vm_start, vma->vm_end, 1);
-		vma = vma->vm_next;
-	}
 }