bnx2x: Fix set-but-unused variables.

The variable 'rc' is set but unused in bnx2x_timer().

Similarly for 'hc_index_p' in bnx2x_init_sb(), and 'port' in
bnx2x_get_hwinfo().

Just kill them off.

Signed-off-by: David S. Miller <davem@davemloft.net>