xdp: remove KNOT_XDP_LISTEN_PORT_MASK from enum to mute pedantic warning

src/libknot/xdp/bpf-consts.h

@@ -25,8 +25,9 @@
 
 #pragma once
 
+#define KNOT_XDP_LISTEN_PORT_MASK    0xFFFF0000  /*!< Listen port option mask. */
+
 enum {
-	KNOT_XDP_LISTEN_PORT_MASK  = 0xFFFF0000, /*!< Listen port option mask. */
 	KNOT_XDP_LISTEN_PORT_TCP   = 1 << 16,    /*!< Apply to TCP. */
 	KNOT_XDP_LISTEN_PORT_PASS  = 1 << 17,    /*!< Pass incoming messages to ports >= port value. */
 	KNOT_XDP_LISTEN_PORT_DROP  = 1 << 18,    /*!< Drop incoming messages to ports >= port value. */