iwlwifi: make config const

Writing to the global config structures
is always wrong. To protect against such
mistakes in the future, mark them const.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-ucode.c b/drivers/net/wireless/iwlwifi/iwl-ucode.c
index b16efc0..206a61c 100644
--- a/drivers/net/wireless/iwlwifi/iwl-ucode.c
+++ b/drivers/net/wireless/iwlwifi/iwl-ucode.c
@@ -692,7 +692,7 @@
 
 int __must_check iwl_request_firmware(struct iwl_nic *nic, bool first)
 {
-	struct iwl_cfg *cfg = cfg(nic);
+	const struct iwl_cfg *cfg = cfg(nic);
 	const char *name_pre = cfg->fw_name_pre;
 	char tag[8];
 
@@ -1045,7 +1045,7 @@
 static void iwl_ucode_callback(const struct firmware *ucode_raw, void *context)
 {
 	struct iwl_nic *nic = context;
-	struct iwl_cfg *cfg = cfg(nic);
+	const struct iwl_cfg *cfg = cfg(nic);
 	struct iwl_fw *fw = &nic->fw;
 	struct iwl_ucode_header *ucode;
 	int err;