Makefile: Fix getting misspell code when already installed (#7434)

Grouping misspell installation code so it won't executed when
misspell is found in the current system.

Makefile

@@ -13,10 +13,10 @@ checks:
 	@(env bash $(PWD)/buildscripts/checkgopath.sh)
 
 getdeps:
-	@mkdir -p $(GOPATH)/bin
-	@echo "Installing golint" && which golint || go get -u golang.org/x/lint/golint
-	@echo "Installing staticcheck" && which staticcheck || wget --quiet -O $(GOPATH)/bin/staticcheck https://github.com/dominikh/go-tools/releases/download/2019.1/staticcheck_linux_amd64 && chmod +x $(GOPATH)/bin/staticcheck
-	@echo "Installing misspell" && which misspell || wget --quiet https://github.com/client9/misspell/releases/download/v0.3.4/misspell_0.3.4_linux_64bit.tar.gz && tar xvf misspell_0.3.4_linux_64bit.tar.gz && mv misspell $(GOPATH)/bin/misspell && chmod +x $(GOPATH)/bin/misspell && rm -r misspell_0.3.4_linux_64bit.tar.gz
+	@mkdir -p ${GOPATH}/bin
+	@which golint 1>/dev/null || (echo "Installing golint" && go get -u golang.org/x/lint/golint)
+	@which staticcheck 1>/dev/null || (echo "Installing staticcheck" && wget --quiet -O ${GOPATH}/bin/staticcheck https://github.com/dominikh/go-tools/releases/download/2019.1/staticcheck_linux_amd64 && chmod +x ${GOPATH}/bin/staticcheck)
+	@which misspell 1>/dev/null || (echo "Installing misspell" && wget --quiet https://github.com/client9/misspell/releases/download/v0.3.4/misspell_0.3.4_linux_64bit.tar.gz && tar xf misspell_0.3.4_linux_64bit.tar.gz && mv misspell ${GOPATH}/bin/misspell && chmod +x ${GOPATH}/bin/misspell && rm -f misspell_0.3.4_linux_64bit.tar.gz)
 
 crosscompile:
 	@(env bash $(PWD)/buildscripts/cross-compile.sh)