selftests/net: temporarily disable io_uring zc test

We're going to change API, to avoid build problems with a couple of
following commits, disable io_uring testing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/12b7507223df04fbd12aa05fc0cb544b51d7ed79.1662027856.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

tools/testing/selftests/net/io_uring_zerocopy_tx.c

@@ -36,6 +36,8 @@
 #include <sys/un.h>
 #include <sys/wait.h>
 
+#if 0
+
 #define NOTIF_TAG 0xfffffffULL
 #define NONZC_TAG 0
 #define ZC_TAG 1
@@ -603,3 +605,10 @@ int main(int argc, char **argv)
 		error(1, 0, "unknown cfg_test %s", cfg_test);
 	return 0;
 }
+
+#else
+int main(int argc, char **argv)
+{
+	return 0;
+}
+#endif