makefile: start treating vet as a check

This adds vet as a check in `make check`. Additionally, it moves
the run of vet in `make test` and `make manager` to after the build.
I wanted to remove it entirely from that line but decided not to make
such a big change. Vet needs to run after compile because it prints
a 'vet: ' prefix on compile errors [1], and this messes up tools -
specifically my vim quickfix. Doing the build first makes you fix
real compiler errors and then real vet errors found afterward get
emitted without the annoying prefix.

[1]: golang/go#34142

Signed-off-by: John Mulligan <jmulligan@redhat.com>

Makefile

@@ -43,11 +43,11 @@ endif
 all: manager build-integration-tests
 
 # Run tests
-test: generate vet manifests
+test: generate manifests vet
 	hack/test.sh
 
 # Build manager binary
-manager: generate vet build
+manager: generate build vet
 
 build:
 	go build -o bin/manager -ldflags "-X main.Version=$(GIT_VERSION) -X main.CommitID=$(COMMIT_ID)"  main.go
@@ -170,7 +170,7 @@ bundle-build:
 
 .PHONY: check check-revive check-format
 
-check: check-revive check-format
+check: check-revive check-format vet
 
 check-format:
 	! gofmt $(CHECK_GOFMT_FLAGS) . | sed 's,^,formatting error: ,' | grep 'go$$'