Use 'make format FLAGS=--check' instead of 'make checkformat'

Author: gvanrossum-ms

.github/workflows/ci.yml

@@ -19,4 +19,4 @@ jobs:
 
       - run: make check
       - run: make test
-      - run: make checkformat
+      - run: make format FLAGS=--check

Makefile

@@ -8,10 +8,7 @@ all: venv format check test build
 
 .PHONY: format
 format: venv
-	.venv/bin/black typeagent test tools
-
-checkformat: venv
-	.venv/bin/black --check typeagent test tools
+	.venv/bin/black typeagent test tools $(FLAGS)
 
 .PHONY: check
 check: venv