Makefile: rm $(allpackages)

This was added by commit 993cbf9db but since some time ago (go 1.13
for sure, but may be earlier) is no longer needed since all the tools
are correctly skipping vendor subdir.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Makefile

@@ -59,8 +59,8 @@ dbuild: runcimage
 		$(RUNC_IMAGE) make clean all
 
 lint:
-	$(GO) vet $(allpackages)
-	$(GO) fmt $(allpackages)
+	$(GO) vet ./...
+	$(GO) fmt ./...
 
 man:
 	man/md2man-all.sh
@@ -82,7 +82,7 @@ unittest: runcimage
 		$(RUNC_IMAGE) make localunittest TESTFLAGS=$(TESTFLAGS)
 
 localunittest: all
-	$(GO) test -timeout 3m -tags "$(BUILDTAGS)" $(TESTFLAGS) -v $(allpackages)
+	$(GO) test -timeout 3m -tags "$(BUILDTAGS)" $(TESTFLAGS) -v ./...
 
 integration: runcimage
 	$(CONTAINER_ENGINE) run $(CONTAINER_ENGINE_RUN_FLAGS) \
@@ -138,7 +138,7 @@ clean:
 validate:
 	script/validate-gofmt
 	script/validate-c
-	$(GO) vet $(allpackages)
+	$(GO) vet ./...
 
 ci: validate test release
 
@@ -164,7 +164,3 @@ localcross:
 	CGO_ENABLED=1 GOARCH=arm GOARM=7 CC=arm-linux-gnueabihf-gcc $(GO_BUILD) -o runc-armhf .
 	CGO_ENABLED=1 GOARCH=arm64 CC=aarch64-linux-gnu-gcc         $(GO_BUILD) -o runc-arm64 .
 	CGO_ENABLED=1 GOARCH=ppc64le CC=powerpc64le-linux-gnu-gcc   $(GO_BUILD) -o runc-ppc64le .
-
-# memoize allpackages, so that it's executed only once and only if used
-_allpackages = $(shell $(GO) list ./... | grep -v vendor)
-allpackages = $(if $(__allpackages),,$(eval __allpackages := $$(_allpackages)))$(__allpackages)