test: Move console silencing to test_pre_run()

We already have a function for silencing the console during tests. Use
this from test_pre_run() and drop this code from the driver model tests.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/test-dm.c b/test/dm/test-dm.c
index d1d83e3..fdd35f6 100644
--- a/test/dm/test-dm.c
+++ b/test/dm/test-dm.c
@@ -66,7 +66,6 @@
 static int dm_do_test(struct unit_test_state *uts, struct unit_test *test,
 		      bool of_live)
 {
-	struct sandbox_state *state = state_get_current();
 	const char *fname = strrchr(test->file, '/') + 1;
 
 	printf("Test: %s: %s%s\n", test->name, fname,
@@ -75,13 +74,10 @@
 
 	ut_assertok(test_pre_run(uts, test));
 
-	if (!state->show_test_output)
-		gd->flags |= GD_FLG_SILENT;
 	test->func(uts);
 
 	ut_assertok(test_post_run(uts, test));
 
-	gd->flags &= ~(GD_FLG_SILENT | GD_FLG_RECORD);
 	state_set_skip_delays(false);
 
 	ut_assertok(dm_test_destroy(uts));
diff --git a/test/test-main.c b/test/test-main.c
index db0d82e..e273777 100644
--- a/test/test-main.c
+++ b/test/test-main.c
@@ -50,13 +50,14 @@
 			return -EAGAIN;
 		}
 	}
+	ut_silence_console(uts);
 
 	return 0;
 }
 
 int test_post_run(struct unit_test_state *uts, struct unit_test *test)
 {
-	gd->flags &= ~GD_FLG_RECORD;
+	ut_unsilence_console(uts);
 
 	return 0;
 }