iwlwifi: acpi: don't return valid pointer as an ERR_PTR

iwl_acpi_get_wifi_pkg() may return a valid pointer (meaning success),
while `tbl_rev` is invalid (equel to 1).
In this case, we will treat that as an error.
Subsequent "users" of this "error code" may either check for nonzero
(good; pointers are never zero) or negative
(bad; pointers may be "positive") fix that by splitting the if statement.
First check if IS_ERR(wifi_pkg) and then if tbl_rev != 0.
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210210142629.1c8c4b58c932.I147373f6fd364606b0282af8d402c722eb917225@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

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

@@ -478,11 +478,16 @@ int iwl_sar_get_wrds_table(struct iwl_fw_runtime *fwrt)
 
 	wifi_pkg = iwl_acpi_get_wifi_pkg(fwrt->dev, data,
 					 ACPI_WRDS_WIFI_DATA_SIZE, &tbl_rev);
-	if (IS_ERR(wifi_pkg) || tbl_rev != 0) {
+	if (IS_ERR(wifi_pkg)) {
 		ret = PTR_ERR(wifi_pkg);
 		goto out_free;
 	}
 
+	if (tbl_rev != 0) {
+		ret = -EINVAL;
+		goto out_free;
+	}
+
 	if (wifi_pkg->package.elements[1].type != ACPI_TYPE_INTEGER) {
 		ret = -EINVAL;
 		goto out_free;
@@ -516,11 +521,16 @@ int iwl_sar_get_ewrd_table(struct iwl_fw_runtime *fwrt)
 
 	wifi_pkg = iwl_acpi_get_wifi_pkg(fwrt->dev, data,
 					 ACPI_EWRD_WIFI_DATA_SIZE, &tbl_rev);
-	if (IS_ERR(wifi_pkg) || tbl_rev != 0) {
+	if (IS_ERR(wifi_pkg)) {
 		ret = PTR_ERR(wifi_pkg);
 		goto out_free;
 	}
 
+	if (tbl_rev != 0) {
+		ret = -EINVAL;
+		goto out_free;
+	}
+
 	if (wifi_pkg->package.elements[1].type != ACPI_TYPE_INTEGER ||
 	    wifi_pkg->package.elements[2].type != ACPI_TYPE_INTEGER) {
 		ret = -EINVAL;
@@ -576,11 +586,17 @@ int iwl_sar_get_wgds_table(struct iwl_fw_runtime *fwrt)
 
 	wifi_pkg = iwl_acpi_get_wifi_pkg(fwrt->dev, data,
 					 ACPI_WGDS_WIFI_DATA_SIZE, &tbl_rev);
-	if (IS_ERR(wifi_pkg) || tbl_rev > 1) {
+
+	if (IS_ERR(wifi_pkg)) {
 		ret = PTR_ERR(wifi_pkg);
 		goto out_free;
 	}
 
+	if (tbl_rev > 1) {
+		ret = -EINVAL;
+		goto out_free;
+	}
+
 	fwrt->geo_rev = tbl_rev;
 	for (i = 0; i < ACPI_NUM_GEO_PROFILES; i++) {
 		for (j = 0; j < ACPI_GEO_TABLE_SIZE; j++) {