HID: wiimote: fix DRM debug-attr to correctly parse input

We need to correctly zero-terminate the input to parse it. Otherwise, we
always end up interpreting it as numbers.
Furthermore, we actually want hexadecimal numbers instead of decimal. As
it is a debugfs interface, we can change the API at any time.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-wiimote-debug.c b/drivers/hid/hid-wiimote-debug.c
index 6e76a2c..c13fb5b 100644
--- a/drivers/hid/hid-wiimote-debug.c
+++ b/drivers/hid/hid-wiimote-debug.c
@@ -141,7 +141,7 @@
 	if (copy_from_user(buf, u, len))
 		return -EFAULT;
 
-	buf[15] = 0;
+	buf[len] = 0;
 
 	for (i = 0; i < WIIPROTO_REQ_MAX; ++i) {
 		if (!wiidebug_drmmap[i])
@@ -151,7 +151,7 @@
 	}
 
 	if (i == WIIPROTO_REQ_MAX)
-		i = simple_strtoul(buf, NULL, 10);
+		i = simple_strtoul(buf, NULL, 16);
 
 	spin_lock_irqsave(&dbg->wdata->state.lock, flags);
 	dbg->wdata->state.flags &= ~WIIPROTO_FLAG_DRM_LOCKED;