Replace bazel :gofmt target with direct invocation

The rule to run from the workspace is broken by the .bazel-bin change,
but bazel now supports direct invocation.

BUILD.bazel

@@ -23,10 +23,3 @@ go_library(
     ],
     importpath = "k8s.io/kops",
 )
-
-load("@io_k8s_repo_infra//defs:run_in_workspace.bzl", "workspace_binary")
-
-workspace_binary(
-    name = "gofmt",
-    cmd = "@go_sdk//:bin/gofmt",
-)

Makefile

@@ -360,7 +360,7 @@ gomod: bazelisk gomod-prereqs
 
 .PHONY: gofmt
 gofmt:
-	find $(KOPS_ROOT) -name "*.go" | grep -v vendor | xargs ${BAZEL} run //:gofmt -- -w -s
+	find $(KOPS_ROOT) -name "*.go" | grep -v vendor | xargs ${BAZEL} run @go_sdk//:bin/gofmt -- -w -s
 
 .PHONY: goimports
 goimports:

hack/verify-gofmt.sh

@@ -18,7 +18,7 @@
 
 cd "${KOPS_ROOT}" || exit 1
 
-bad_files=$(git ls-files "*.go" | grep -v vendor | xargs bazelisk run //:gofmt -- -s -w -l)
+bad_files=$(git ls-files "*.go" | grep -v vendor | xargs bazelisk run @go_sdk//:bin/gofmt -- -s -w -l)
 if [[ -n "${bad_files}" ]]; then
   echo "FAIL: 'make gofmt' needs to be run on the following files: "
   echo "${bad_files}"