iwlwifi: pcie: fix context info freeing

After firmware alive, iwl_trans_pcie_gen2_fw_alive() is called
to free the context info. However, on gen3 that will then free
the context info with the wrong size.

Since we free this allocation later, let it stick around until
the device is stopped for now, freeing some of it earlier is a
separate change.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618105614.afb63fb8cbc1.If4968db8e09f4ce2a1d27a6d750bca3d132d7d70@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>