pdb server: Return negative carrierid for failures. Clang format

(cherry picked from commit 88b698e0f62c39ed60af9f0a4fb3ca2dc6867d8f)

utils/pdbt/pdb_server.c

@@ -151,7 +151,7 @@ int udp_server(int so)
 				carrierid = lookup_number(msg.bdy.payload);
 
 				/* check if not found pdb_id */
-				if(carrierid == 0) {
+				if(carrierid == -1) {
 					pdb_msg_format_send(&msg, PDB_VERSION_1, PDB_TYPE_REPLY_ID,
 							PDB_CODE_NOT_FOUND, htons(msg.hdr.id), NULL, 0);
 					goto msg_send;

utils/pdbt/pdb_server_backend.c

@@ -44,8 +44,8 @@ carrier_t lookup_number(char *number)
 	carrier_t carrierid;
 	int nmatch = dtm_longest_match(mroot, number, strlen(number), &carrierid);
 	if(nmatch <= 0) {
-		/* nothing found - return id 0 */
-		carrierid = 0;
+		/* nothing found - return id -1 */
+		carrierid = -1;
 	}
 	LINFO("request='%s', nmatch=%ld, carrier=%ld\n", number, (long int)nmatch,
 			(long int)carrierid);