6lowpan: fix a small formatting issue

This formatting issue was introduced with commit
d4ac32365dcbfd341a87eae444c26679f889249a

Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index c9c3f3d..f4969d7 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -104,7 +104,7 @@
 struct lowpan_dev_info {
 	struct net_device	*real_dev; /* real WPAN device ptr */
 	struct mutex		dev_list_mtx; /* mutex for list ops */
-	unsigned short fragment_tag;
+	unsigned short		fragment_tag;
 };
 
 struct lowpan_dev_record {