testsuite: improve assert report
diff --git a/testsuite/testsuite.h b/testsuite/testsuite.h
index e12170e..9db1d1a 100644
--- a/testsuite/testsuite.h
+++ b/testsuite/testsuite.h
@@ -122,7 +122,7 @@
 #define assert_return(expr, r)						\
 	do {								\
 		if ((!(expr))) {					\
-			ERR("Failed assertion: " #expr "%s:%d %s",	\
+			ERR("Failed assertion: " #expr " %s:%d %s\n",	\
 			    __FILE__, __LINE__, __PRETTY_FUNCTION__);	\
 			return (r);					\
 		}							\