Some makefile fixes (#442)

* Generate and build before linting

Generated files may require some formatting that happens during
linting. Also missing generated files may result in linter failures.

Building can shake out any syntax/semantic errors and report them in a
much nicer way than the linter does. Which is exactly the reason the
build was running before linters before the Makefile simplification.

* Make stringer tool a dep of generate target, not lint

Lint target does not use the stringer utility - it is being used by go
generate.

Makefile

@@ -25,7 +25,7 @@ $(TOOLS_DIR)/misspell: go.mod go.sum tools.go
 $(TOOLS_DIR)/stringer: go.mod go.sum tools.go
 	go build -o $(TOOLS_DIR)/stringer golang.org/x/tools/cmd/stringer
 
-precommit: lint generate build examples test
+precommit: generate build lint examples test
 
 .PHONY: test-with-coverage
 test-with-coverage:
@@ -84,7 +84,7 @@ examples:
 	done
 
 .PHONY: lint
-lint: $(TOOLS_DIR)/golangci-lint $(TOOLS_DIR)/misspell $(TOOLS_DIR)/stringer
+lint: $(TOOLS_DIR)/golangci-lint $(TOOLS_DIR)/misspell
 	set -e; for dir in $(ALL_GO_MOD_DIRS); do \
 	  echo "golangci-lint in $${dir}"; \
 	  (cd "$${dir}" && \
@@ -98,5 +98,5 @@ lint: $(TOOLS_DIR)/golangci-lint $(TOOLS_DIR)/misspell $(TOOLS_DIR)/stringer
 	    go mod tidy); \
 	done
 
-generate:
+generate: $(TOOLS_DIR)/stringer
 	PATH="$(abspath $(TOOLS_DIR)):$${PATH}" go generate ./...