wifi: iwlwifi: return negative -EINVAL instead of positive EINVAL

The '-' character is missing in -EINVAL.

Fixes: fc7214c3 ("wifi: iwlwifi: read DSM functions from UEFI")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://msgid.link/f0391316-ab30-4664-96ac-03445ab2aeba@moroto.mountainSigned-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/fw/uefi.c

@@ -679,7 +679,7 @@ int iwl_uefi_get_dsm(struct iwl_fw_runtime *fwrt, enum iwl_dsm_funcs func,
 		     u32 *value)
 {
 	struct uefi_cnv_var_general_cfg *data;
-	int ret = EINVAL;
+	int ret = -EINVAL;
 
 	/* Not supported function index */
 	if (func >= DSM_FUNC_NUM_FUNCS || func == 5)