sandbox: test: Show hex values on failure

Quite a few tests use addresses or hex values for comparisons. Add hex
output for test failures, e.g.:

   0x55ca22fa == reg: Expected 0x55ca22fa (1439310586),
	got 0x55ea22fb (1441407739)

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

include/test/ut.h

@@ -61,7 +61,8 @@ void ut_failf(struct unit_test_state *uts, const char *fname, int line,
 	if (val1 != val2) {						\
 		ut_failf(uts, __FILE__, __LINE__, __func__,		\
 			 #expr1 " == " #expr2,				\
-			 "Expected %d, got %d", val1, val2);		\
+			 "Expected %#x (%d), got %#x (%d)", val1, val1,	\
+			 val2, val2);					\
 		return CMD_RET_FAILURE;					\
 	}								\
 }