bgpd: Modify attr->flag to be 64 bit

With the some current bgp drafts the Attribute number has
surpassed 32.  Which is a bit unfortunate in that we keep
track of the attributes via a bitfield based on the attribute #.

For the moment since I am not aware of Attribute #'s being
greater than 64, convert the flag to 64 bit and allow the
bit shifting to know about it.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

bgpd/bgp_attr.h

@@ -163,7 +163,7 @@ struct attr
   unsigned long refcnt;
 
   /* Flag of attribute is set or not. */
-  u_int32_t flag;
+  u_int64_t flag;
 
   /* Apart from in6_addr, the remaining static attributes */
   struct in_addr nexthop;
@@ -204,7 +204,7 @@ struct transit
   u_char *val;
 };
 
-#define ATTR_FLAG_BIT(X)  (1 << ((X) - 1))
+#define ATTR_FLAG_BIT(X)  (1ULL << ((X) - 1))
 
 #define BGP_CLUSTER_LIST_LENGTH(attr)				\
   (((attr)->flag & ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST)) ?	\