alpha: fix alloc_zeroed_user_highpage_movable()

Due to a typo, the final argument to alloc_page_vma() didn't refer to a
real variable.  This only affected CONFIG_NUMA, which was marked BROKEN in
2006 and removed from alpha in 2021.  Found due to a refactoring patch.

Link: https://lkml.kernel.org/r/20220504182857.4013401-4-willy@infradead.org


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>