relay: use strscpy() is more robust and safer

The implementation of strscpy() is more robust and safer.  That's now the
recommended way to copy NUL terminated strings.

Link: https://lkml.kernel.org/r/202211220853259244666@zte.com.cnSigned-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: wuchi <wuchi.zero@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kernel/relay.c

@@ -507,7 +507,7 @@ struct rchan *relay_open(const char *base_filename,
 	chan->private_data = private_data;
 	if (base_filename) {
 		chan->has_base_filename = 1;
-		strlcpy(chan->base_filename, base_filename, NAME_MAX);
+		strscpy(chan->base_filename, base_filename, NAME_MAX);
 	}
 	chan->cb = cb;
 	kref_init(&chan->kref);
@@ -578,7 +578,7 @@ int relay_late_setup_files(struct rchan *chan,
 	if (!chan || !base_filename)
 		return -EINVAL;
 
-	strlcpy(chan->base_filename, base_filename, NAME_MAX);
+	strscpy(chan->base_filename, base_filename, NAME_MAX);
 
 	mutex_lock(&relay_channels_mutex);
 	/* Is chan already set up? */