Fix misc-macro-parentheses warnings.

Bug: 28705665
Change-Id: Ie514abfe12bea065658da3706aad8b4c9c0a93c7
diff --git a/tests/hwc/cnativewindow.c b/tests/hwc/cnativewindow.c
index 5c16afb..5b1d78e 100644
--- a/tests/hwc/cnativewindow.c
+++ b/tests/hwc/cnativewindow.c
@@ -37,7 +37,7 @@
 static int trace_level = 1;
 
 #define _TRACE(n,fmt...) \
-	do { if (trace_level >= n) fprintf(stderr, "CNW: " fmt); } while (0)
+	do { if (trace_level >= (n)) fprintf(stderr, "CNW: " fmt); } while (0)
 
 #define ERROR(fmt...) _TRACE(0, fmt)
 #define INFO(fmt...) _TRACE(1, fmt)