mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops

It is more clear to use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs file
operation rather than DEFINE_SIMPLE_ATTRIBUTE.

Link: http://lkml.kernel.org/r/1572403660-44718-1-git-send-email-zhongjiang@huawei.comSigned-off-by: zhong jiang <zhongjiang@huawei.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hwpoison-inject.c

@@ -67,8 +67,8 @@ static int hwpoison_unpoison(void *data, u64 val)
 	return unpoison_memory(val);
 }
 
-DEFINE_SIMPLE_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
-DEFINE_SIMPLE_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
+DEFINE_DEBUGFS_ATTRIBUTE(hwpoison_fops, NULL, hwpoison_inject, "%lli\n");
+DEFINE_DEBUGFS_ATTRIBUTE(unpoison_fops, NULL, hwpoison_unpoison, "%lli\n");
 
 static void pfn_inject_exit(void)
 {