net: stmmac: xgmac: Fix missing return

If FPE is supposed to be disabled we need to return after disabling it.

Fixes: f0e56c8d ("net: stmmac: xgmac3+: Add support for Frame Preemption")
Signed-off-by: NJose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c

@@ -1421,6 +1421,7 @@ static void dwxgmac3_fpe_configure(void __iomem *ioaddr, u32 num_txq,
 		value &= ~XGMAC_EFPE;
 
 		writel(value, ioaddr + XGMAC_FPE_CTRL_STS);
+		return;
 	}
 
 	value = readl(ioaddr + XGMAC_RXQ_CTRL1);