stmmac: fixed a compilation error when use the external timer

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/stmmac/stmmac_timer.c b/drivers/net/stmmac/stmmac_timer.c
index b838c65..679f61f 100644
--- a/drivers/net/stmmac/stmmac_timer.c
+++ b/drivers/net/stmmac/stmmac_timer.c
@@ -63,7 +63,7 @@
 
 	stmmac_rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
 	if (stmmac_rtc == NULL) {
-		pr_error("open rtc device failed\n");
+		pr_err("open rtc device failed\n");
 		return -ENODEV;
 	}
 
@@ -71,7 +71,7 @@
 
 	/* Periodic mode is not supported */
 	if ((rtc_irq_set_freq(stmmac_rtc, &stmmac_task, tm->freq) < 0)) {
-		pr_error("set periodic failed\n");
+		pr_err("set periodic failed\n");
 		rtc_irq_unregister(stmmac_rtc, &stmmac_task);
 		rtc_class_close(stmmac_rtc);
 		return -1;