ppc/spapr: Fix possible pa_features memory overflow

Coverity reports a possible memory overflow in spapr_dt_pa_features().
This should not be a true bug since DAWR1 cap is only be true for
CPU_POWERPC_LOGICAL_3_10. Add an assertion to ensure any bug there is
caught.

Resolves: Coverity CID 1593722
Fixes: 5f361ea ("ppc: spapr: Enable 2nd DAWR on Power10 pSeries machine")
Reviewed-By: Shivaprasad G Bhat <[email protected]>
Reviewed-by: Cédric Le Goater <[email protected]>
Signed-off-by: Nicholas Piggin <[email protected]>

Author: npiggin

hw/ppc/spapr.c

@@ -296,6 +296,7 @@ static void spapr_dt_pa_features(SpaprMachineState *spapr,
         pa_features[40 + 2] &= ~0x80; /* Radix MMU */
     }
     if (spapr_get_cap(spapr, SPAPR_CAP_DAWR1)) {
+        g_assert(pa_size > 66);
         pa_features[66] |= 0x80;
     }