ice: fix memory leak if register_netdev_fails

The ice_setup_pf_sw function can cause a memory leak if register_netdev
fails, due to accidentally failing to free the VSI rings. Fix the memory
leak by using ice_vsi_release, ensuring we actually go through the full
teardown process.

This should be safe even if the netdevice is not registered because we
will have set the netdev pointer to NULL, ensuring ice_vsi_release won't
call unregister_netdev.

An alternative fix would be moving management of the PF VSI netdev into
the main VSI setup code. This is complicated and likely requires
significant refactor in how we manage VSIs

Fixes: 3a858ba3 ("ice: Add support for VSI allocation and deallocation")
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>