tests: respect --enable/--disable-download for Avocado

Pass the content of $mkvenv_flags (which is either "--online"
or empty) down to tests/Makefile.include.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -968,14 +968,14 @@ meson="$(cd pyvenv/bin; pwd)/meson"
 
 # Conditionally ensure Sphinx is installed.
 
-mkvenv_flags=""
-if test "$download" = "enabled" -a "$docs" = "enabled" ; then
-    mkvenv_flags="--online"
+mkvenv_online_flag=""
+if test "$download" = "enabled" ; then
+    mkvenv_online_flag=" --online"
 fi
 
 if test "$docs" != "disabled" ; then
     if ! $mkvenv ensuregroup \
-         $mkvenv_flags \
+         $(test "$docs" = "enabled" && echo "$mkvenv_online_flag") \
          ${source_path}/pythondeps.toml docs;
     then
         if test "$docs" = "enabled" ; then
@@ -1634,6 +1634,7 @@ if test "$container" != no; then
 fi
 echo "SUBDIRS=$subdirs" >> $config_host_mak
 echo "PYTHON=$python" >> $config_host_mak
+echo "MKVENV_ENSUREGROUP=$mkvenv ensuregroup $mkvenv_online_flag" >> $config_host_mak
 echo "GENISOIMAGE=$genisoimage" >> $config_host_mak
 echo "MESON=$meson" >> $config_host_mak
 echo "NINJA=$ninja" >> $config_host_mak

tests/Makefile.include

@@ -111,7 +111,7 @@ quiet-venv-pip = $(quiet-@)$(call quiet-command-run, \
 
 $(TESTS_VENV_TOKEN): $(SRC_PATH)/pythondeps.toml
 	$(call quiet-venv-pip,install -e "$(SRC_PATH)/python/")
-	$(PYTHON) python/scripts/mkvenv.py ensuregroup --online $< avocado
+	$(MKVENV_ENSUREGROUP) $< avocado
 	$(call quiet-command, touch $@)
 
 $(TESTS_RESULTS_DIR):