mm/mmap: change do_vmi_align_munmap() for maple tree iterator changes

The maple tree iterator clean up is incompatible with the way
do_vmi_align_munmap() expects it to behave.  Update the expected behaviour
to map now since the change will work currently.

Link: https://lkml.kernel.org/r/20230518145544.1722059-23-Liam.Howlett@oracle.comSigned-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/mmap.c

@@ -2388,7 +2388,12 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
 #endif
 	}
 
-	next = vma_next(vmi);
+	if (vma_iter_end(vmi) > end)
+		next = vma_iter_load(vmi);
+
+	if (!next)
+		next = vma_next(vmi);
+
 	if (unlikely(uf)) {
 		/*
 		 * If userfaultfd_unmap_prep returns an error the vmas