rde and eigrpe should use exit(3) instead of _exit(2)

Since recently these processes call exec() after fork(), so they should
stop using _exit(2) and use exit(3) instead when shutting down.

ok claudio@

eigrpe.c

@@ -195,7 +195,7 @@ eigrpe_shutdown(void)
 	free(pkt_ptr);
 
 	log_info("eigrp engine exiting");
-	_exit(0);
+	exit(0);
 }
 
 /* imesg */

log.c

@@ -157,10 +157,7 @@ fatal(const char *emsg)
 			logit(LOG_CRIT, "fatal in %s: %s",
 			    procnames[eigrpd_process], emsg);
 
-	if (eigrpd_process == PROC_MAIN)
-		exit(1);
-	else				/* parent copes via SIGCHLD */
-		_exit(1);
+	exit(1);
 }
 
 void

rde.c

@@ -142,7 +142,7 @@ rde_shutdown(void)
 	free(iev_main);
 
 	log_info("route decision engine exiting");
-	_exit(0);
+	exit(0);
 }
 
 int