include sys/resource.h where needed

We use functions from sys/resource.h in misc applets, but don't include
the header.  This breaks building with newer glibc versions, so add the
include where needed.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

networking/ntpd.c

@@ -46,6 +46,7 @@
 #include "libbb.h"
 #include <math.h>
 #include <netinet/ip.h> /* For IPTOS_LOWDELAY definition */
+#include <sys/resource.h> /* setpriority */
 #include <sys/timex.h>
 #ifndef IPTOS_LOWDELAY
 # define IPTOS_LOWDELAY 0x10