e2e: remove sh in spawnCmd

certain shells claim the ppid for expect processes which interferes with
signals

e2e/ctl_v2_test.go

@@ -284,7 +284,7 @@ func etcdctlLs(clus *etcdProcessCluster, key string, quorum bool) error {
 }
 
 func etcdctlWatch(clus *etcdProcessCluster, key, value string, noSync bool) <-chan error {
-	cmdArgs := append(etcdctlPrefixArgs(clus), "watch", "--after-index 1", key)
+	cmdArgs := append(etcdctlPrefixArgs(clus), "watch", "--after-index=1", key)
 	if noSync {
 		cmdArgs = append(cmdArgs, "--no-sync")
 	}

e2e/ctl_v3_test.go

@@ -513,7 +513,7 @@ func ctlV3Version(cx ctlCtx) error {
 }
 
 func ctlV3EpHealth(cx ctlCtx) error {
-	cmdArgs := append(cx.PrefixArgs(), "endpoint health")
+	cmdArgs := append(cx.PrefixArgs(), "endpoint", "health")
 	lines := make([]string, cx.epc.cfg.clusterSize)
 	for i := range lines {
 		lines[i] = "is healthy"

e2e/etcd_test.go

@@ -416,8 +416,7 @@ func (epc *etcdProcessCluster) Close() (err error) {
 }
 
 func spawnCmd(args []string) (*expect.ExpectProcess, error) {
-	cmdargs := append([]string{"-c"}, strings.Join(args, " "))
-	return expect.NewExpect("/bin/sh", cmdargs...)
+	return expect.NewExpect(args[0], args[1:]...)
 }
 
 func spawnWithExpect(args []string, expected string) error {