hw/ppc/spapr.c: consecutive 'spapr->patb_entry = 0' statements

In ppc_spapr_reset(), if the guest is using HPT, the code was executing:

    } else {
        spapr->patb_entry = 0;
        spapr_setup_hpt_and_vrma(spapr);
    }

And, at the end of spapr_setup_hpt_and_vrma:

    /* We're setting up a hash table, so that means we're not radix */
    spapr->patb_entry = 0;

Resulting in spapr->patb_entry being assigned to 0 twice in a row.

Given that 'spapr_setup_hpt_and_vrma' is also called inside
'spapr_check_setup_free_hpt' of spapr_hcall.c, this trivial patch removes
the 'patb_entry = 0' assignment from the 'else' clause inside ppc_spapr_reset
to avoid this behavior.

Signed-off-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>