Merge pull request #9334 from FRRouting/mergify/bp/stable/7.5/pr-9214

zebra: bugfix of error quit of zebra, due to no nexthop ACTIVE (backport #9214)

Author: donaldsharp

zebra/zebra_fpm.c

@@ -995,7 +995,6 @@ static int zfpm_build_route_updates(void)
 			data_len = zfpm_encode_route(dest, re, (char *)data,
 						     buf_end - data, &msg_type);
 
-			assert(data_len);
 			if (data_len) {
 				hdr->msg_type = msg_type;
 				msg_len = fpm_data_len_to_msg_len(data_len);
@@ -1006,6 +1005,9 @@ static int zfpm_build_route_updates(void)
 					zfpm_g->stats.route_adds++;
 				else
 					zfpm_g->stats.route_dels++;
+			} else {
+				zlog_err("%s: Encoding Prefix: %pRN No valid nexthops",
+					 __func__, dest->rnode);
 			}
 		}