test: Handle driver model reinit in test_pre_run()

For driver model tests we want to reinit the data structures so that
everything is in a known state before the test runs. This avoids one test
changing something that breaks a subsequent tests.

Move the call for this into test_pre_run().

Signed-off-by: Simon Glass <sjg@chromium.org>

include/test/test.h

@@ -15,6 +15,7 @@
  * @fail_count: Number of tests that failed
  * @start: Store the starting mallinfo when doing leak test
  * @priv: A pointer to some other info some suites want to track
+ * @of_live: true to use livetree if available, false to use flattree
  * @of_root: Record of the livetree root node (used for setting up tests)
  * @expect_str: Temporary string used to hold expected string value
  * @actual_str: Temporary string used to hold actual string value
@@ -24,6 +25,7 @@ struct unit_test_state {
 	struct mallinfo start;
 	void *priv;
 	struct device_node *of_root;
+	bool of_live;
 	char expect_str[256];
 	char actual_str[256];
 };