test: fix port selection to disable grep output

diff --git a/test/system/test.common b/test/system/test.common
index 1e488195408052386e0b5253bd94fcce420b4cf1..4e5fa0246b90dabd2120102d5072afc94d7bf3ea 100644 (file)
--- a/test/system/test.common
+++ b/test/system/test.common
@@ -180,7 +180,7 @@ get_free_port() {
 
        while true; do
                port=$((RANDOM % 10000 + 10000))
-               netstat -aln | grep '^\(tcp\|udp\).*[:.]'"$port " && continue
+               netstat -aln | grep -q '^\(tcp\|udp\).*[:.]'"$port " && continue
                break
        done