mm/vmalloc.c: use "high-order" in description non 0-order pages

In many places, in the comments, we use both "higher-order" and
"high-order" to describe the non 0-order pages.  That is confusing,
because a "higher-order" statement does not reflect what it is compared
with.

Link: https://lkml.kernel.org/r/20240906095049.3486-1-urezki@gmail.comSigned-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Suggested-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/vmalloc.c

@@ -3570,7 +3570,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 			break;
 
 		/*
-		 * Higher order allocations must be able to be treated as
+		 * High-order allocations must be able to be treated as
 		 * independent small pages by callers (as they can with
 		 * small-page vmallocs). Some drivers do their own refcounting
 		 * on vmalloc_to_page() pages, some use page->mapping,
@@ -3633,7 +3633,7 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 	page_order = vm_area_page_order(area);
 
 	/*
-	 * Higher order nofail allocations are really expensive and
+	 * High-order nofail allocations are really expensive and
 	 * potentially dangerous (pre-mature OOM, disruptive reclaim
 	 * and compaction etc.
 	 *