bridge: use __u16 in if_bridge.h

We should use "__u16" instead of "u16" in the user-space visable
header.

Cc: Vlad Yasevich <vyasevic@redhat.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_bridge.h

@@ -124,8 +124,8 @@ enum {
 #define BRIDGE_VLAN_INFO_UNTAGGED	(1<<2)	/* VLAN egresses untagged */
 
 struct bridge_vlan_info {
-	u16 flags;
-	u16 vid;
+	__u16 flags;
+	__u16 vid;
 };
 
 /* Bridge multicast database attributes