wifi: iwlwifi: Fix firmware version handling

On my system the arithmetic done on the firmware numbers
results in a negative number, but since the types are
unsigned it gets interpreted as a large positive number.

The end result is that the firmware gets rejected and wifi
is defunct.

Switch to signed types to handle this case correctly.

iwlwifi 0000:0c:00.0: Driver unable to support your firmware API. Driver supports FW core 4294967294..2, firmware is 2.
iwlwifi 0000:0c:00.0: Direct firmware load for iwlwifi-5000-4.ucode failed with error -2
iwlwifi 0000:0c:00.0: Direct firmware load for iwlwifi-5000-3.ucode failed with error -2
iwlwifi 0000:0c:00.0: Direct firmware load for iwlwifi-5000-2.ucode failed with error -2
iwlwifi 0000:0c:00.0: Direct firmware load for iwlwifi-5000-1.ucode failed with error -2
iwlwifi 0000:0c:00.0: no suitable firmware found!
iwlwifi 0000:0c:00.0: minimum version required: iwlwifi-5000-1
iwlwifi 0000:0c:00.0: maximum version supported: iwlwifi-5000-5
iwlwifi 0000:0c:00.0: check git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git

Cc: linux-wireless@vger.kernel.org
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Fixes: 5f708cc ("wifi: iwlwifi: add a new FW file numbering scheme")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cherry-picked-for: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/171

Author: vsyrjala

drivers/net/wireless/intel/iwlwifi/iwl-drv.c

@@ -1599,7 +1599,7 @@ static void _iwl_op_mode_stop(struct iwl_drv *drv)
  */
 static void iwl_req_fw_callback(const struct firmware *ucode_raw, void *context)
 {
-	unsigned int min_core, max_core, loaded_core;
+	int min_core, max_core, loaded_core;
 	struct iwl_drv *drv = context;
 	struct iwl_fw *fw = &drv->fw;
 	const struct iwl_ucode_header *ucode;
@@ -1678,7 +1678,7 @@ static void iwl_req_fw_callback(const struct firmware *ucode_raw, void *context)
 	if (loaded_core < min_core || loaded_core > max_core) {
 		IWL_ERR(drv,
 			"Driver unable to support your firmware API. "
-			"Driver supports FW core %u..%u, firmware is %u.\n",
+			"Driver supports FW core %d..%d, firmware is %d.\n",
 			min_core, max_core, loaded_core);
 		goto try_again;
 	}