arch/unicore32/kernel/module.c: use __vmalloc_node_range() instead of __vmalloc_area()

__vmalloc_area() has already been removed from upstream kernel, need
use __vmalloc_node_range() instead of.

The related commit: "d0a21265

 mm: unify module_alloc code for vmalloc".

The related error (allmodconfig for unicore32):

    CC      arch/unicore32/kernel/module.o
  arch/unicore32/kernel/module.c: In function 'module_alloc' :
  arch/unicore32/kernel/module.c:34: error: implicit declaration of function '__vmalloc_area'
  arch/unicore32/kernel/module.c:34: warning: return makes pointer from integer without a cast
  make[1]: *** [arch/unicore32/kernel/module.o] Error 1
  make: *** [arch/unicore32/kernel] Error 2

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Xuetao Guan <gxt@mprc.pku.edu.cn>
Signed-off-by: Xuetao Guan <gxt@mprc.pku.edu.cn>