wifi: iwlwifi: return ERR_PTR from opmode start()

wifi: iwlwifi: return ERR_PTR from opmode start()

In order to restrict the retry loops for timeouts, first
pass the error code up using ERR_PTR(). This of course
requires all existing functions to be updated accordingly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20241227095718.3fe5031d5784.I7307996c91dac69619ff9c616b8a077423fac19f@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>