Cover the scenario when we cannot insert a socket into the sockmap, because
it has it is using ULP. Failed insert should not have any effect on the ULP
state. This is a regression test.
Signed-off-by: NJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/r/20220623091231.417138-1-jakub@cloudflare.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>