dm: test: Show the test filename when running

Show the filename of the test being run. Skip the path and show just the
base name.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/test-main.c b/test/dm/test-main.c
index 2848673..10d2706 100644
--- a/test/dm/test-main.c
+++ b/test/dm/test-main.c
@@ -75,8 +75,9 @@
 static int dm_do_test(struct unit_test_state *uts, struct unit_test *test)
 {
 	struct sandbox_state *state = state_get_current();
+	const char *fname = strrchr(test->file, '/') + 1;
 
-	printf("Test: %s\n", test->name);
+	printf("Test: %s: %s\n", test->name, fname);
 	ut_assertok(dm_test_init(uts));
 
 	uts->start = mallinfo();