Fix two warnings about self-assignment in libc. These normally only

trigger with clang, when you either use -save-temps, or ccache.

Reported by:	Sevan / Venture37 <venture37@gmail.com>
MFC after:	3 days

lib/libc/include/port_before.h

@@ -17,6 +17,6 @@
                 var = _u.v; \
         } while (0)
 
-#define UNUSED(x) (x) = (x)
+#define UNUSED(x) (void)(x)
 
 #endif /* _PORT_BEFORE_H_ */

lib/libc/net/getaddrinfo.c

@@ -464,7 +464,7 @@ getaddrinfo(const char *hostname, const char *servname,
 		}
 		error = get_portmatch(pai, servname);
 		if (error)
-			ERR(error);
+			goto bad;
 
 		*pai = ai0;
 	}