libbpf: Prevent deprecation warnings in xsk.c

xsk.c is using own APIs that are marked for deprecation internally.
Given xsk.c and xsk.h will be gone in libbpf 1.0, there is no reason to
do public vs internal function split just to avoid deprecation warnings.
So just add a pragma to silence deprecation warnings (until the code is
removed completely).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124193233.3115996-4-andrii@kernel.org

Author: anakryiko

tools/lib/bpf/xsk.c

@@ -35,6 +35,11 @@
 #include "libbpf_internal.h"
 #include "xsk.h"
 
+/* entire xsk.h and xsk.c is going away in libbpf 1.0, so ignore all internal
+ * uses of deprecated APIs
+ */
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+
 #ifndef SOL_XDP
  #define SOL_XDP 283
 #endif