iwlwifi: don't treat a bool as an error code

iwl_trans_grab_nic_access returns a boolean. So ret should
explicitely set to an error code and not rely on the value
returned by iwl_trans_grab_nic_access.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/dvm/mac80211.c

@@ -459,11 +459,11 @@ static int iwlagn_mac_resume(struct ieee80211_hw *hw)
 	base = priv->device_pointers.error_event_table;
 	if (iwlagn_hw_valid_rtc_data_addr(base)) {
 		spin_lock_irqsave(&priv->trans->reg_lock, flags);
-		ret = iwl_trans_grab_nic_access(priv->trans, true);
-		if (likely(ret == 0)) {
+		if (iwl_trans_grab_nic_access(priv->trans, true)) {
 			iwl_write32(priv->trans, HBUS_TARG_MEM_RADDR, base);
 			status = iwl_read32(priv->trans, HBUS_TARG_MEM_RDAT);
 			iwl_trans_release_nic_access(priv->trans);
+			ret = 0;
 		}
 		spin_unlock_irqrestore(&priv->trans->reg_lock, flags);