zdtm: compile a test before constructing a new root

A binary is required to get shared library dependencies
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -223,6 +223,7 @@ start_test()
 			ZDTM_ROOT=`readlink -f $ZDTM_ROOT`
 			mount --bind . $ZDTM_ROOT || return 1
 		fi
+		make -C $tdir $tname
 		construct_root $ZDTM_ROOT $tdir/$tname || return 1
 	(	export ZDTM_NEWNS=1
 		export ZDTM_PIDFILE=$TPID