bnx2x: use the right constant

[ Upstream commit dd612f18a49b63af8b3a5f572d999bdb197385bc ]

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: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>