lib/tests/ltp.sh: fix ltp compile error

Error:
/usr/bin/ld: /tmp/lkp/ccRzQ6Hc.o: in function `main':
/tmp/lkp/ltp/src/ltp/testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/rpc/rpc_createdestroy_svc_destroy/rpc_svc_destroy.c:48: undefined reference to `svcfd_create'
collect2: error: ld returned 1 exit status
make: *** [../../../../../../../../include/mk/rules.mk:45: rpc_svc_destroy] Error 1

Reason:
should link libtirpc-dev.

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

lib/tests/ltp.sh

@@ -19,8 +19,6 @@ build_ltp()
 	./configure --prefix=$1
 	make || return
 
-	# fix rpc test cases, linking to libtirpc-dev will make the tests failed in debian
-	sed -i "s/^LDLIBS/#LDLIBS/" testcases/network/rpc/rpc-tirpc/tests_pack/Makefile.inc || return
 	rebuild testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/rpc/rpc_createdestroy_svc_destroy || return
 	rebuild testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/rpc/rpc_createdestroy_svcfd_create || return
 	rebuild testcases/network/rpc/rpc-tirpc/tests_pack/rpc_suite/rpc/rpc_regunreg_xprt_register || return