Skip a doctest that doesn't work in mock environments

rust-nix.spec

@@ -464,8 +464,8 @@ use the "zerocopy" feature of the "%{crate}" crate.
 
 %if %{with check}
 %check
-# skip a test that is not supported in virtualized environments
-%cargo_test -- -- --skip sys::test_socket::test_af_alg_cipher
+# * skip two tests that don't work in mock environments
+%cargo_test -- -- --skip sys::test_socket::test_af_alg_cipher --skip src/sys/socket/mod.rs
 %endif
 
 %changelog