test: Drop the function for running exit tests

Use the new suite-runner to run these tests instead.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/cmd_ut.c b/test/cmd_ut.c
index 155b187..387aacb 100644
--- a/test/cmd_ut.c
+++ b/test/cmd_ut.c
@@ -138,7 +138,7 @@
 #if defined(CONFIG_UT_ENV)
 	SUITE(env),
 #endif
-	SUITE_CMD(exit, do_ut_exit),
+	SUITE(exit),
 #ifdef CONFIG_CMD_FDT
 	SUITE_CMD(fdt, do_ut_fdt),
 #endif