Makefile: fix golangci-lint install issues

With commit 300242c, my intention was to use whatever version of
golangci-lint is available locally, and if not (which is usually the
case in CI), install the version recommended by the Makefile.

The code was changed since, and currently has two issues wrt how
golangci-lint is installed:

1. golangci-lint prints version without v prefix (e.g.
   "... version 1.23.45 ..."), while grep looks for v1.23.45.
   As a result, golangci-lint is *always* reinstalled.

2. If a newer golangci-lint version is installed locally, running
   "make lint" will downgrade it. This is not what most developers
   would expect.

Let's fix both. A version in the Makefile is now minimally
required version, and no attempt to downgrade is made.

Fixes: ea3afbc ("Build changes for golang 1.18")
Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

Makefile

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 GO := go
-GOLANGCI_VER := v1.56.2
+GOLANGCI_VER := 1.56.2
 GO_TEST ?= $(GO) test $(or $(GO_FLAGS),-race)
 arch ?= $(shell go env GOARCH)
 
@@ -82,9 +82,15 @@ presubmit: lint
 
 lint:
 	@# This assumes GOPATH/bin is in $PATH -- if not, the target will fail.
-	@if ! golangci-lint version | grep $(GOLANGCI_VER); then \
-		echo ">> installing golangci-lint $(GOLANGCI_VER)"; \
-		curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $$(go env GOPATH)/bin $(GOLANGCI_VER); \
+	@# Extract the current golangci-lint version (empty if not installed),
+	@# then use GNU sort to check if GOT >= GOLANGCI_VER.
+	@GOT=$$(golangci-lint version 2>/dev/null | sed 's/^.* version \([^ ]*\) .*$$/\1/'); \
+	if ! printf $(GOLANGCI_VER)\\n$$GOT\\n | sort --version-sort --check=quiet; then \
+		echo ">> upgrading golangci-lint from $$GOT to $(GOLANGCI_VER)"; \
+		curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $$(go env GOPATH)/bin v$(GOLANGCI_VER); \
+		GOT=$(GOLANGCI_VER); \
+	else \
+		echo ">> using installed golangci-lint $$GOT >= $(GOLANGCI_VER)"; \
 	fi
 	@echo ">> running golangci-lint using configuration at .golangci.yml"
 	@golangci-lint run