mm/memory.c: convert to DEFINE_DEBUGFS_ATTRIBUTE

The preferred strategy to define debugfs attributes is to use the
DEFINE_DEBUGFS_ATTRIBUTE() macro and to use debugfs_create_file_unsafe().

Link: http://lkml.kernel.org/r/20170528145948.32127-1-y.pronenko@gmail.com
Signed-off-by: Yevgen Pronenko <y.pronenko@gmail.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c

@@ -3262,14 +3262,14 @@ static int fault_around_bytes_set(void *data, u64 val)
 		fault_around_bytes = PAGE_SIZE; /* rounddown_pow_of_two(0) is undefined */
 	return 0;
 }
-DEFINE_SIMPLE_ATTRIBUTE(fault_around_bytes_fops,
+DEFINE_DEBUGFS_ATTRIBUTE(fault_around_bytes_fops,
 		fault_around_bytes_get, fault_around_bytes_set, "%llu\n");
 
 static int __init fault_around_debugfs(void)
 {
 	void *ret;
 
-	ret = debugfs_create_file("fault_around_bytes", 0644, NULL, NULL,
+	ret = debugfs_create_file_unsafe("fault_around_bytes", 0644, NULL, NULL,
 			&fault_around_bytes_fops);
 	if (!ret)
 		pr_warn("Failed to create fault_around_bytes in debugfs");