iwlwifi: pcie: fix locking when "HW not ready"

If we run into this error path, we shouldn't unlock the mutex
since it's not locked since. Fix this.

Fixes: a6bd005 ("iwlwifi: pcie: fix RF-Kill vs. firmware load race")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/iwlwifi.20220128142706.5d16821d1433.Id259699ddf9806459856d6aefbdbe54477aecffd@changeid

drivers/net/wireless/intel/iwlwifi/pcie/trans.c

@@ -1329,8 +1329,7 @@ static int iwl_trans_pcie_start_fw(struct iwl_trans *trans,
 	/* This may fail if AMT took ownership of the device */
 	if (iwl_pcie_prepare_card_hw(trans)) {
 		IWL_WARN(trans, "Exit HW not ready\n");
-		ret = -EIO;
-		goto out;
+		return -EIO;
 	}
 
 	iwl_enable_rfkill_int(trans);