fix minor races in workspace tests

The improved err scanner loop in meta causes these to race. There's no
need to write back to the same commands struct, so just use a new
instance in each iteration.

command/workspace_command_test.go

@@ -74,14 +74,14 @@ func TestWorkspace_createAndList(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	newCmd := &WorkspaceNewCommand{}
-
 	envs := []string{"test_a", "test_b", "test_c"}
 
 	// create multiple workspaces
 	for _, env := range envs {
 		ui := new(cli.MockUi)
-		newCmd.Meta = Meta{Ui: ui}
+		newCmd := &WorkspaceNewCommand{
+			Meta: Meta{Ui: ui},
+		}
 		if code := newCmd.Run([]string{env}); code != 0 {
 			t.Fatalf("bad: %d\n\n%s", code, ui.ErrorWriter)
 		}
@@ -179,14 +179,14 @@ func TestWorkspace_createInvalid(t *testing.T) {
 	defer os.RemoveAll(td)
 	defer testChdir(t, td)()
 
-	newCmd := &WorkspaceNewCommand{}
-
 	envs := []string{"test_a*", "test_b/foo", "../../../test_c", "好_d"}
 
 	// create multiple workspaces
 	for _, env := range envs {
 		ui := new(cli.MockUi)
-		newCmd.Meta = Meta{Ui: ui}
+		newCmd := &WorkspaceNewCommand{
+			Meta: Meta{Ui: ui},
+		}
 		if code := newCmd.Run([]string{env}); code == 0 {
 			t.Fatalf("expected failure: \n%s", ui.OutputWriter)
 		}