Fix vendor bogon where one of dhcp_option_ev_name()'s formal parameter

types did not match the prototype.

(Note: this is one bug that an Ada compiler would have found as when you
typedef a new type, the new type is not assignment compatabile with the
type used to make it up.  C should only be so featureful.)

contrib/isc-dhcp/client/dhclient.c

@@ -2173,7 +2173,7 @@ void client_envadd (struct client_state *client,
 
 int dhcp_option_ev_name (buf, buflen, option)
 	char *buf;
-	unsigned buflen;
+	size_t buflen;
 	struct option *option;
 {
 	int i;