net: stmmac: gmac4: bitrev32 returns u32

The bitrev32 function returns an u32 var, not an int. Fix it.

Fixes: 477286b53f55 ("stmmac: add GMAC4 core support")
Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index 5a7b0ac..66e60c7 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -432,7 +432,7 @@
 			 * bits used depends on the hardware configuration
 			 * selected at core configuration time.
 			 */
-			int bit_nr = bitrev32(~crc32_le(~0, ha->addr,
+			u32 bit_nr = bitrev32(~crc32_le(~0, ha->addr,
 					ETH_ALEN)) >> (32 - mcbitslog2);
 			/* The most significant bit determines the register to
 			 * use (H/L) while the other 5 bits determine the bit