Remove fmt and vet checks from CI (#13063)

* Remove fmt and vet checks from CI

- golangci-lint already does the vet and fmt checks. Remove those
as it is redundant now.
- Also start running golangci-lint as part of the CI pipeline now
just as an extra layer of reliability.

* Incorporate review comments

* Adding golangci install to Jenkinsfile.pr too

* dummy commit to test jenkins

* Trying after cd to directory

* Fix ineffective assign

Makefile

@@ -149,31 +149,10 @@ else
 endif
 
 
-govet: ## Runs govet against all packages.
-	@echo Running GOVET
-	env GO111MODULE=off $(GO) get golang.org/x/tools/go/analysis/passes/shadow/cmd/shadow
-	$(GO) vet $(GOFLAGS) $(ALL_PACKAGES) || exit 1
-	$(GO) vet -vettool=$(GOPATH)/bin/shadow $(GOFLAGS) $(ALL_PACKAGES) || exit 1
+plugin-checker:
 	$(GO) run $(GOFLAGS) ./plugin/checker
 
-gofmt: ## Runs gofmt against all packages.
-	@echo Running GOFMT
-
-	@for package in $(TE_PACKAGES) $(EE_PACKAGES); do \
-		echo "Checking "$$package; \
-		files=$$($(GO) list $(GOFLAGS) -f '{{range .GoFiles}}{{$$.Dir}}/{{.}} {{end}}' $$package); \
-		if [ "$$files" ]; then \
-			gofmt_output=$$(gofmt -d -s $$files 2>&1); \
-			if [ "$$gofmt_output" ]; then \
-				echo "$$gofmt_output"; \
-				echo "gofmt failure"; \
-				exit 1; \
-			fi; \
-		fi; \
-	done
-	@echo "gofmt success"; \
-
-golangci-lint: ## Run golangci-lint on codebasis
+golangci-lint: ## Run golangci-lint on codebase
 # https://stackoverflow.com/a/677212/1027058 (check if a command exists or not)
 	@if ! [ -x "$$(command -v golangci-lint)" ]; then \
 		echo "golangci-lint is not installed. Please see https://github.com/golangci/golangci-lint#install for installation instructions."; \
@@ -229,8 +208,7 @@ check-licenses: ## Checks license status.
 check-prereqs: ## Checks prerequisite software status.
 	./scripts/prereq-check.sh
 
-# TODO: remove govet and gofmt checks once golangci-lint is being enforced.
-check-style: govet gofmt check-licenses check-plugin-golint ## Runs govet and gofmt against all packages and also ensures plugin package golint compliant
+check-style: golangci-lint plugin-checker check-licenses check-plugin-golint ## Runs golangci against all packages and also ensures plugin package golint compliant
 
 check-plugin-golint: # Checks if golint returns any uncompliant code for any file that starts with plugin/helpers
 	@! golint ./plugin/ | grep plugin/helpers