Add -installsuffix netgo in static build

This fix adds `-installsuffix netgo` in static build in combination
of `-tags netgo`. See following for the reason:
golang/go#9369 (comment)

Signed-off-by: Yong Tang <[email protected]>

Author: yongtang

Makefile

@@ -39,8 +39,8 @@ contrib/cmd/recvtty/recvtty: $(SOURCES)
 	$(GO) build -buildmode=pie $(EXTRA_FLAGS) -ldflags "-X main.gitCommit=${COMMIT} -X main.version=${VERSION} $(EXTRA_LDFLAGS)" -tags "$(BUILDTAGS)" -o contrib/cmd/recvtty/recvtty ./contrib/cmd/recvtty
 
 static: $(SOURCES)
-	CGO_ENABLED=1 $(GO) build $(EXTRA_FLAGS) -tags "$(BUILDTAGS) netgo cgo static_build" -ldflags "-w -extldflags -static -X main.gitCommit=${COMMIT} -X main.version=${VERSION} $(EXTRA_LDFLAGS)" -o runc .
-	CGO_ENABLED=1 $(GO) build $(EXTRA_FLAGS) -tags "$(BUILDTAGS) netgo cgo static_build" -ldflags "-w -extldflags -static -X main.gitCommit=${COMMIT} -X main.version=${VERSION} $(EXTRA_LDFLAGS)" -o contrib/cmd/recvtty/recvtty ./contrib/cmd/recvtty
+	CGO_ENABLED=1 $(GO) build $(EXTRA_FLAGS) -tags "$(BUILDTAGS) netgo cgo static_build" -installsuffix netgo -ldflags "-w -extldflags -static -X main.gitCommit=${COMMIT} -X main.version=${VERSION} $(EXTRA_LDFLAGS)" -o runc .
+	CGO_ENABLED=1 $(GO) build $(EXTRA_FLAGS) -tags "$(BUILDTAGS) netgo cgo static_build" -installsuffix netgo -ldflags "-w -extldflags -static -X main.gitCommit=${COMMIT} -X main.version=${VERSION} $(EXTRA_LDFLAGS)" -o contrib/cmd/recvtty/recvtty ./contrib/cmd/recvtty
 
 release:
 	script/release.sh -r release/$(VERSION) -v $(VERSION)