FROMLIST: BACKPORT: mm: Set up vma iterator for vma_iter_prealloc() calls

Set the correct limits for vma_iter_prealloc() calls so that the maple
tree can be smarter about how many nodes are needed.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>

Link: https://lore.kernel.org/lkml/20230601021605.2823123-11-Liam.Howlett@oracle.com/


[surenb: remove vma_iter-related changes not present in 6.1 kernel]

Bug: 274059236
Change-Id: I05d1989e35b2e72b9346743f290da66739b3ee59
Signed-off-by: Suren Baghdasaryan <surenb@google.com>