bgpd: do not check attr in bgp_packet_attribute

Fix the following coverity issue. attr cannot be NULL.

> CID 1568376 (sonic-net#1 of 1): Dereference before null check (REVERSE_INULL)
> check_after_deref: Null-checking attr suggests that it may be null, but it has already been dereferenced on all paths leading to the check.

Fixes: 8b531b1 ("bgpd: store and send bgp link-state attributes")
Signed-off-by: Louis Scalbert <[email protected]>

Author: louis-6wind

bgpd/bgp_attr.c

@@ -4982,7 +4982,7 @@ bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer,
 	}
 
 	/* BGP Link-State */
-	if (attr && attr->link_state) {
+	if (attr->link_state) {
 		stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
 		stream_putc(s, BGP_ATTR_LINK_STATE);
 		stream_putc(s, attr->link_state->length);