dtc: Fix FAIL() macro varargs

The way the checking subsystem FAIL() macro is currently implemented
it must take at least one paramater after the format string.  This
patch corrects the problem.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

checks.c

@@ -101,11 +101,11 @@ static inline void check_msg(struct check *c, const char *fmt, ...)
 	fprintf(stderr, "\n");
 }
 
-#define FAIL(c, fmt, ...) \
+#define FAIL(c, ...) \
 	do { \
 		TRACE((c), "\t\tFAILED at %s:%d", __FILE__, __LINE__); \
 		(c)->status = FAILED; \
-		check_msg((c), fmt, __VA_ARGS__); \
+		check_msg((c), __VA_ARGS__); \
 	} while (0)
 
 static void check_nodes_props(struct check *c, struct node *dt, struct node *node)