- Understand EADDRINUSE, and forget EDQUOT. [1]

- Add description for EEXIST.
- Change description for ENOBUFS. Routing socket can return
  this error for many different reasons, including general
  memory shortage, mbuf memory shortage and rtentry zone.

PR:		kern/64090 [1]

sbin/route/route.c

@@ -768,11 +768,15 @@ newroute(argc, argv)
 				err = "entry in use";
 				break;
 			case ENOBUFS:
-				err = "routing table overflow";
+				err = "not enough memory";
 				break;
-			case EDQUOT: /* handle recursion avoidance in rt_setgate() */
+			case EADDRINUSE:
+				/* handle recursion avoidance in rt_setgate() */
 				err = "gateway uses the same route";
 				break;
+			case EEXIST:
+				err = "route already in table";
+				break;
 			default:
 				err = strerror(oerrno);
 				break;