selftests/xsk: Rename xsk_xdp_metadata.h to xsk_xdp_common.h

Rename the header file to a generic name so that it can be used by all
future XDP programs. Ensure that the xsk_xdp_common.h header file includes
include guards.

Signed-off-by: Tushar Vyavahare <tushar.vyavahare@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20230927135241.2287547-3-tushar.vyavahare@intel.com

tools/testing/selftests/bpf/progs/xsk_xdp_progs.c

@@ -3,7 +3,7 @@
 
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
-#include "xsk_xdp_metadata.h"
+#include "xsk_xdp_common.h"
 
 struct {
 	__uint(type, BPF_MAP_TYPE_XSKMAP);

tools/testing/selftests/bpf/xsk_xdp_common.h

@@ -1,5 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 
+#ifndef XSK_XDP_COMMON_H_
+#define XSK_XDP_COMMON_H_
+
 struct xdp_info {
 	__u64 count;
 } __attribute__((aligned(32)));
+
+#endif /* XSK_XDP_COMMON_H_ */

tools/testing/selftests/bpf/xskxceiver.c

@@ -102,7 +102,7 @@
 #include <bpf/bpf.h>
 #include <linux/filter.h>
 #include "../kselftest.h"
-#include "xsk_xdp_metadata.h"
+#include "xsk_xdp_common.h"
 
 static const char *MAC1 = "\x00\x0A\x56\x9E\xEE\x62";
 static const char *MAC2 = "\x00\x0A\x56\x9E\xEE\x61";