Eliminate last three uses of varargs.h in the tree. These three files

were including varargs.h file but did not use any of its macros,
so they escaped the clean-up before.

libexec/ftpd/popen.c

@@ -58,7 +58,6 @@ static const char rcsid[] =
 #include "pathnames.h"
 #include <syslog.h>
 #include <time.h>
-#include <varargs.h>
 
 #define	MAXUSRARGS	100
 #define	MAXGLOBARGS	1000

libexec/rpc.rquotad/rquotad.c

@@ -28,7 +28,6 @@ static const char rcsid[] =
 #include <unistd.h>
 
 #include <syslog.h>
-#include <varargs.h>
 
 #include <ufs/ufs/quota.h>
 #include <rpc/rpc.h>

usr.bin/lock/lock.c

@@ -70,7 +70,6 @@ __FBSDID("$FreeBSD$");
 #include <syslog.h>
 #include <termios.h>
 #include <unistd.h>
-#include <varargs.h>
 
 #define	TIMEOUT	15