Update golangci-lint

* Update to latest release.
* Remove `install -d` workaround[0].

[0]: golangci/golangci-lint#672

Signed-off-by: Ben Kochie <superq@gmail.com>

Makefile.common

@@ -83,7 +83,7 @@ PROMU_URL     := https://github.com/prometheus/promu/releases/download/v$(PROMU_
 
 GOLANGCI_LINT :=
 GOLANGCI_LINT_OPTS ?=
-GOLANGCI_LINT_VERSION ?= v1.18.0
+GOLANGCI_LINT_VERSION ?= v1.28.2
 # golangci-lint only supports linux, darwin and windows platforms on i386/amd64.
 # windows isn't included here because of the path separator being different.
 ifeq ($(GOHOSTOS),$(filter $(GOHOSTOS),linux darwin))
@@ -274,7 +274,6 @@ ifdef GOLANGCI_LINT
 $(GOLANGCI_LINT):
 	mkdir -p $(FIRST_GOPATH)/bin
 	curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/$(GOLANGCI_LINT_VERSION)/install.sh \
-		| sed -e '/install -d/d' \
 		| sh -s -- -b $(FIRST_GOPATH)/bin $(GOLANGCI_LINT_VERSION)
 endif