stmmac: fix 'lenght' typo in comments and code

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/stmmac/dwmac100.c b/drivers/net/stmmac/dwmac100.c
index 82dde77..ac48ed78 100644
--- a/drivers/net/stmmac/dwmac100.c
+++ b/drivers/net/stmmac/dwmac100.c
@@ -265,7 +265,7 @@
 		ret = discard_frame;
 
 	if (unlikely(p->des01.rx.length_error)) {
-		x->rx_lenght++;
+		x->rx_length++;
 		ret = discard_frame;
 	}
 	if (unlikely(p->des01.rx.mii_error)) {