net: stmmac: dwmac1000: Clear unused address entries

In case we don't use a given address entry we need to clear it because
it could contain previous values that are no longer valid.

Found out while running stmmac selftests.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c

@@ -217,6 +217,12 @@ static void dwmac1000_set_filter(struct mac_device_info *hw,
 					    GMAC_ADDR_LOW(reg));
 			reg++;
 		}
+
+		while (reg <= perfect_addr_number) {
+			writel(0, ioaddr + GMAC_ADDR_HIGH(reg));
+			writel(0, ioaddr + GMAC_ADDR_LOW(reg));
+			reg++;
+		}
 	}
 
 #ifdef FRAME_FILTER_DEBUG