tests: Add missing dependencies on $(qapi-py)

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/tests/Makefile b/tests/Makefile
index 666aee2..6d2f2e5 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -301,22 +301,22 @@
 	libqemuutil.a libqemustub.a
 
 tests/test-qapi-types.c tests/test-qapi-types.h :\
-$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py
+$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-types.py $(qapi-py)
 	$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-types.py \
 		$(gen-out-type) -o tests -p "test-" -i $<, \
 		"  GEN   $@")
 tests/test-qapi-visit.c tests/test-qapi-visit.h :\
-$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-visit.py
+$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-visit.py $(qapi-py)
 	$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-visit.py \
 		$(gen-out-type) -o tests -p "test-" -i $<, \
 		"  GEN   $@")
 tests/test-qmp-commands.h tests/test-qmp-marshal.c :\
-$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-commands.py
+$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-commands.py $(qapi-py)
 	$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-commands.py \
 		$(gen-out-type) -o tests -p "test-" -i $<, \
 		"  GEN   $@")
 tests/test-qapi-event.c tests/test-qapi-event.h :\
-$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-event.py
+$(SRC_PATH)/tests/qapi-schema/qapi-schema-test.json $(SRC_PATH)/scripts/qapi-event.py $(qapi-py)
 	$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-event.py \
 		$(gen-out-type) -o tests -p "test-" -i $<, \
 		"  GEN   $@")