fix NL80211_ATTR_MAX_SCAN_IE_LEN attribute size

The kernel provides this as a u16, not a u32,
but unfortunately the problem only shows up
on big endian machines.
diff --git a/info.c b/info.c
index ce85514..d842c26 100644
--- a/info.c
+++ b/info.c
@@ -142,7 +142,7 @@
 		       nla_get_u8(tb_msg[NL80211_ATTR_MAX_NUM_SCAN_SSIDS]));
 	if (tb_msg[NL80211_ATTR_MAX_SCAN_IE_LEN])
 		printf("\tmax scan IEs length: %d bytes\n",
-		       nla_get_u32(tb_msg[NL80211_ATTR_MAX_SCAN_IE_LEN]));
+		       nla_get_u16(tb_msg[NL80211_ATTR_MAX_SCAN_IE_LEN]));
 
 	if (tb_msg[NL80211_ATTR_WIPHY_FRAG_THRESHOLD]) {
 		unsigned int frag;