iwlwifi: remember the last uCode sysassert error code

When sysassert happen, uCode will report the error code,
driver dump the information to dmesg. Here also remember
the last error code for future reference.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 0ee8f51..86017ed 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -575,10 +575,10 @@
 		priv->isr_stats.hw);
 	pos += scnprintf(buf + pos, bufsz - pos, "SW Error:\t\t\t %u\n",
 		priv->isr_stats.sw);
-	if (priv->isr_stats.sw > 0) {
+	if (priv->isr_stats.sw || priv->isr_stats.hw) {
 		pos += scnprintf(buf + pos, bufsz - pos,
 			"\tLast Restarting Code:  0x%X\n",
-			priv->isr_stats.sw_err);
+			priv->isr_stats.err_code);
 	}
 #ifdef CONFIG_IWLWIFI_DEBUG
 	pos += scnprintf(buf + pos, bufsz - pos, "Frame transmitted:\t\t %u\n",