pkg/ltp/PKGBUILD: fix ltp/src/rusers/rpc.rstatd-4.0.1 compile error

Error:
rup.c:29:10: fatal error: rpc/rpc.h: No such file or directory
   29 | #include <rpc/rpc.h>
      |          ^~~~~~~~~~~
compilation terminated.
make[1]: *** [Makefile:325: rup.o] Error 1

Reason:
add libtirpc-dev include path and library.

Signed-off-by: Jie2x Zhou <jie2x.zhou@intel.com>
Signed-off-by: Philip Li <philip.li@intel.com>

pkg/ltp/PKGBUILD

@@ -40,6 +40,8 @@ build_rusers()
 	cd rpc*/ || return
 	./configure --prefix="${benchmark_path}"/netkit-rusers
 
+	sed -i '/^DEFAULT_INCLUDES =/ s/$/ -I\/usr\/include\/tirpc/' Makefile
+	sed -i '/^LIBS =/ s/$/ -ltirpc/' Makefile
 	make
 }