fix RTT for specific platforms

pkg/interfaces/tcp_common.go

@@ -0,0 +1,14 @@
+//go:build !linux
+// +build !linux
+
+package interfaces
+
+import (
+	"time"
+)
+
+// platformGetRTT is defined in OS-specific files
+// Default implementation for non-Linux platforms
+func platformGetRTT(fd uintptr) time.Duration {
+	return 0
+}