tests: fix test-checkstyle to check plugin tests

Type: fix

Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
Change-Id: I93eb0ae4338247fa2479f8e419483d1593436dc7
diff --git a/test/Makefile b/test/Makefile
index ca861b3..d8bbf4d 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -267,7 +267,7 @@
 	@virtualenv $(VENV_PATH) -p python3
 	@bash -c "source $(VENV_PATH)/bin/activate && python3 -m pip install pycodestyle"
 	@bash -c "source $(VENV_PATH)/bin/activate &&\
-		pycodestyle --show-source --ignore=W504,E126,E241,E226,E305,E704,E741,E722 --exclude=$(WS_ROOT)/test/_*.py -v $(WS_ROOT)/test/*.py ||\
+		pycodestyle --show-source --ignore=W504,E126,E241,E226,E305,E704,E741,E722 --exclude=$(WS_ROOT)/test/_*.py -v $(WS_ROOT)/test/*.py $(PLUGIN_SRC_DIR)/*/test/*.py ||\
 		(echo \"*******************************************************************\" &&\
 		 echo \"* Test framework PEP8 compliance check FAILED \" &&\
 	         echo \"*******************************************************************\" &&\