iwlwifi: fix *pci_probe error flow

for iwlagn:
- Have to free eeprom of version check fails - otherwise we end up with
  memory leak.
- Include removal of workqueue (created in _setup_deferred_work) in error
  handling.

for iwl3945:
- Fix a few places to jump to correct error handling.
- Reorganize error handling to match with code flow.
- Include iwl_free_channel_map as part of error handling.
- Include releasing eeprom as part of error handling.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>