nommu: remove __GFP_HIGHMEM in vmalloc/vzalloc

mm/nommu.c:
void *__vmalloc(unsigned long size, gfp_t gfp_mask)
{
	/*
	 *  You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc()
	 * returns only a logical address.
	 */
	return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM);
}

nommu's __vmalloc just uses kmalloc internally and elimitates
__GFP_HIGHMEM, so it makes no sense to add __GFP_HIGHMEM for nommu's
vmalloc/vzalloc.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Chen Li <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>

mm/nommu.c

@@ -223,7 +223,7 @@ long vread(char *buf, char *addr, unsigned long count)
  */
 void *vmalloc(unsigned long size)
 {
-       return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM);
+       return __vmalloc(size, GFP_KERNEL);
 }
 EXPORT_SYMBOL(vmalloc);
 
@@ -241,7 +241,7 @@ EXPORT_SYMBOL(vmalloc);
  */
 void *vzalloc(unsigned long size)
 {
-	return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
+	return __vmalloc(size, GFP_KERNEL | __GFP_ZERO);
 }
 EXPORT_SYMBOL(vzalloc);