RDMA/mlx5: Fix MR cache initialization error flow

Destroy all previously created cache entries and work queue when rolling
back the MR cache initialization upon an error.

Fixes: 73d09b2f ("RDMA/mlx5: Introduce mlx5r_cache_rb_key")
Signed-off-by: Michael Guralnik <michaelgur@nvidia.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://patch.msgid.link/c41d525fb3c72e28dd38511bf3aaccb5d584063e.1741875692.git.leon@kernel.org


Signed-off-by: Leon Romanovsky <leon@kernel.org>