tools/check: We do need a default for ${PYTHON} as called from

install.sh with PYTHON possibly undefined in the environment.

So we make PYTHON=python the sensible default.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

tools/check/check_python_xml

@@ -3,6 +3,9 @@
 
 . ./funcs.sh
 
+if test -z ${PYTHON}; then
+  PYTHON=python
+fi
 has_or_fail ${PYTHON}
 
 ${PYTHON} -c 'import xml.dom.minidom' 2>/dev/null || \