bnx2x: use the right constant

Nearby code that also tests port suggests that the P0 constant should be
used when port is zero.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e,e1;
@@

* e ? e1 : e1
// </smpl>

Fixes: 6c3218c6 ("bnx2x: Adjust ETS to 578xx")
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c

@@ -588,7 +588,7 @@ static void bnx2x_ets_e3b0_nig_disabled(const struct link_params *params,
 	 * slots for the highest priority.
 	 */
 	REG_WR(bp, (port) ? NIG_REG_P1_TX_ARB_NUM_STRICT_ARB_SLOTS :
-		   NIG_REG_P1_TX_ARB_NUM_STRICT_ARB_SLOTS, 0x100);
+		   NIG_REG_P0_TX_ARB_NUM_STRICT_ARB_SLOTS, 0x100);
 	/* Mapping between the CREDIT_WEIGHT registers and actual client
 	 * numbers
 	 */