pmap_rmt.c: do not undefine _POSIX_SOURCE, it is anyway too late

Signed-off-by: Peter S. Mazinger <ps.m@gmx.net>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

libc/inet/rpc/pmap_rmt.c

@@ -49,7 +49,6 @@ static char sccsid[] = "@(#)pmap_rmt.c 1.21 87/08/27 Copyr 1984 Sun Micro";
 #include <sys/socket.h>
 #include <stdio.h>
 #include <errno.h>
-#undef	 _POSIX_SOURCE		/* Ultrix <sys/param.h> needs --roland@gnu */
 #include <sys/param.h>		/* Ultrix needs before net/if --roland@gnu */
 #include <net/if.h>
 #include <sys/ioctl.h>