iwlwifi: pcie: fix iwl_so_trans_cfg link error when CONFIG_IWLMVM is disabled

Randy reported an error on his randconfig builds:

ERROR: modpost: "iwl_so_trans_cfg" [drivers/net/wireless/intel/iwlwifi/iwlwifi.ko] undefined!

The problem was that when CONFIG_IWLMVM was disabled we were still accessing
iwl_so_trans_cfg. Fix it by moving IS_ENABLED() check before the access.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: 930be4e76f ("iwlwifi: add support for SnJ with Jf devices")
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Luca Coelho <luciano.coelho@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1614236661-20274-1-git-send-email-kvalo@codeaurora.org

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

@@ -1106,6 +1106,8 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		}
 	}
 
+#if IS_ENABLED(CONFIG_IWLMVM)
+
 	/*
 	 * Workaround for problematic SnJ device: sometimes when
 	 * certain RF modules are connected to SnJ, the device ID
@@ -1116,7 +1118,6 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (CSR_HW_REV_TYPE(iwl_trans->hw_rev) == IWL_CFG_MAC_TYPE_SNJ)
 		iwl_trans->trans_cfg = &iwl_so_trans_cfg;
 
-#if IS_ENABLED(CONFIG_IWLMVM)
 	/*
 	 * special-case 7265D, it has the same PCI IDs.
 	 *