Remove DOCKER_EXECDRIVER env

Since --exec-driver flag has been removed, we don't need environment
DOCKER_EXECDRIVER in integration-cli and Makefile any more.

Signed-off-by: Lei Jitang <leijiang@huawei.com>

Makefile

@@ -7,7 +7,6 @@ DOCKER_ENVS := \
 	-e BUILDFLAGS \
 	-e DOCKER_CLIENTONLY \
 	-e DOCKER_DEBUG \
-	-e DOCKER_EXECDRIVER \
 	-e DOCKER_EXPERIMENTAL \
 	-e DOCKER_REMAP_ROOT \
 	-e DOCKER_GRAPHDRIVER \

docs/Makefile

@@ -6,7 +6,6 @@
 DOCKER_ENVS := \
 	-e BUILDFLAGS \
 	-e DOCKER_CLIENTONLY \
-	-e DOCKER_EXECDRIVER \
 	-e DOCKER_GRAPHDRIVER \
 	-e TESTDIRS \
 	-e TESTFLAGS \

hack/make.sh

@@ -212,7 +212,6 @@ test_env() {
 	# use "env -i" to tightly control the environment variables that bleed into the tests
 	env -i \
 		DEST="$DEST" \
-		DOCKER_EXECDRIVER="$DOCKER_EXECDRIVER" \
 		DOCKER_GRAPHDRIVER="$DOCKER_GRAPHDRIVER" \
 		DOCKER_USERLANDPROXY="$DOCKER_USERLANDPROXY" \
 		DOCKER_HOST="$DOCKER_HOST" \

integration-cli/docker_utils.go

@@ -113,7 +113,6 @@ type Daemon struct {
 	stdout, stderr    io.ReadCloser
 	cmd               *exec.Cmd
 	storageDriver     string
-	execDriver        string
 	wait              chan error
 	userlandProxy     bool
 	useDefaultHost    bool
@@ -155,7 +154,6 @@ func NewDaemon(c *check.C) *Daemon {
 		folder:        daemonFolder,
 		root:          daemonRoot,
 		storageDriver: os.Getenv("DOCKER_GRAPHDRIVER"),
-		execDriver:    os.Getenv("DOCKER_EXECDRIVER"),
 		userlandProxy: userlandProxy,
 	}
 }