dm: test: Fix nit with position of backslash

Line up this backslash with all the others.

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

include/test/ut.h

@@ -104,7 +104,7 @@ void ut_failf(struct unit_test_state *uts, const char *fname, int line,
 }
 
 /* Assert that a pointer is not an error pointer */
-#define ut_assertok_ptr(expr) {					\
+#define ut_assertok_ptr(expr) {						\
 	const void *val = (expr);					\
 									\
 	if (IS_ERR(val)) {						\