Nightly can use a different tempdir.

@@ -1269,11 +1269,14 @@
                 echo "$IA32_IHV_WS: not found"
                 args_ok=n
         fi
 fi
 
-TMPDIR="/tmp/nightly.tmpdir.$$"
+if [[ -z "$TMPDIR_ROOT" ]]; then
+        TMPDIR_ROOT="/tmp"
+fi
+TMPDIR="${TMPDIR_ROOT}/nightly.tmpdir.$$"
 export TMPDIR
 rm -rf ${TMPDIR}
 mkdir -p $TMPDIR || exit 1
 chmod 777 $TMPDIR