ia64: don't alias VMALLOC_END to vmalloc_end

If CONFIG_VIRTUAL_MEM_MAP is enabled, ia64 defines macro VMALLOC_END
as unsigned long variable vmalloc_end which is adjusted to prepare
room for vmemmap.  This becomes probnlematic if a local variables
vmalloc_end is defined in some function (not very unlikely) and
VMALLOC_END is used in the function - the function thinks its
referencing the global VMALLOC_END value but would be referencing its
own local vmalloc_end variable.

There's no reason VMALLOC_END should be a macro.  Just define it as an
unsigned long variable if CONFIG_VIRTUAL_MEM_MAP is set to avoid nasty
surprises.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64 <linux-ia64@vger.kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c
index 2f724d2..1341437 100644
--- a/arch/ia64/mm/contig.c
+++ b/arch/ia64/mm/contig.c
@@ -270,8 +270,8 @@
 
 		map_size = PAGE_ALIGN(ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) *
 			sizeof(struct page));
-		vmalloc_end -= map_size;
-		vmem_map = (struct page *) vmalloc_end;
+		VMALLOC_END -= map_size;
+		vmem_map = (struct page *) VMALLOC_END;
 		efi_memmap_walk(create_mem_map_page_table, NULL);
 
 		/*