init: fix wording error in mm_init comment

s/countinuous/contiguous/, reword sentence.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

init/main.c

@@ -449,8 +449,8 @@ void __init __weak thread_info_cache_init(void)
 static void __init mm_init(void)
 {
 	/*
-	 * page_cgroup requires countinous pages as memmap
-	 * and it's bigger than MAX_ORDER unless SPARSEMEM.
+	 * page_cgroup requires contiguous pages,
+	 * bigger than MAX_ORDER unless SPARSEMEM.
 	 */
 	page_cgroup_init_flatmem();
 	mem_init();