ieee802154: reassembly: fix possible buffer overflow

The max_dsize attribute in ctl_table for lowpan_frags_ns_ctl_table is
configured with integer accessing methods. This patch change the
max_dsize attribute to int to avoid a possible buffer overflow.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netns/ieee802154_6lowpan.h

@@ -16,7 +16,7 @@ struct netns_sysctl_lowpan {
 struct netns_ieee802154_lowpan {
 	struct netns_sysctl_lowpan sysctl;
 	struct netns_frags	frags;
-	u16			max_dsize;
+	int			max_dsize;
 };
 
 #endif