test: Rename test-main.c to test-dm.c

This is the main test function for driver model but not for other tests.
Rename the file and the function so this is clear.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/test/dm/Makefile b/test/dm/Makefile
index fd14551..f5cc554 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -2,7 +2,7 @@
 #
 # Copyright (c) 2013 Google, Inc
 
-obj-$(CONFIG_UT_DM) += test-main.o
+obj-$(CONFIG_UT_DM) += test-dm.o
 
 # Tests for particular subsystems - when enabling driver model for a new
 # subsystem you must add sandbox tests here.
diff --git a/test/dm/test-main.c b/test/dm/test-dm.c
similarity index 98%
rename from test/dm/test-main.c
rename to test/dm/test-dm.c
index 560f8d6..71e9cf6 100644
--- a/test/dm/test-main.c
+++ b/test/dm/test-dm.c
@@ -146,7 +146,7 @@
 	return false;
 }
 
-int dm_test_main(const char *test_name)
+int dm_test_run(const char *test_name)
 {
 	struct unit_test *tests = ll_entry_start(struct unit_test, dm_test);
 	const int n_ents = ll_entry_count(struct unit_test, dm_test);
@@ -226,5 +226,5 @@
 	if (argc > 1)
 		test_name = argv[1];
 
-	return dm_test_main(test_name);
+	return dm_test_run(test_name);
 }