selftests/bpf: Fix bpf selftest build warning

On linux-next, build for bpf selftest displays a warning:

Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h'
differs from latest version at 'include/uapi/linux/if_xdp.h'.

Commit 8066e38 ("net: add UAPI to the header guard in various network headers")
changed the header guard from _LINUX_IF_XDP_H to _UAPI_LINUX_IF_XDP_H
in include/uapi/linux/if_xdp.h.

To resolve the warning, update tools/include/uapi/linux/if_xdp.h
to align with the changes in include/uapi/linux/if_xdp.h

Fixes: 8066e38 ("net: add UAPI to the header guard in various network headers")
Reported-by: Venkat Rao Bagalkote <[email protected]>
Closes: https://lore.kernel.org/all/[email protected]/
Tested-by: Venkat Rao Bagalkote <[email protected]>
Signed-off-by: Saket Kumar Bhaskar <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: Saket Kumar Bhaskar

tools/include/uapi/linux/if_xdp.h

@@ -7,8 +7,8 @@
  *	      Magnus Karlsson <[email protected]>
  */
 
-#ifndef _LINUX_IF_XDP_H
-#define _LINUX_IF_XDP_H
+#ifndef _UAPI_LINUX_IF_XDP_H
+#define _UAPI_LINUX_IF_XDP_H
 
 #include <linux/types.h>
 
@@ -180,4 +180,4 @@ struct xdp_desc {
 /* TX packet carries valid metadata. */
 #define XDP_TX_METADATA (1 << 1)
 
-#endif /* _LINUX_IF_XDP_H */
+#endif /* _UAPI_LINUX_IF_XDP_H */