use SPtrArray handling instead of explicit delete[]

use SPtrArray handling instead of explicit delete[]

The warning message from gcc doesn't make that much sense in my reading
as there is no loop which could overflow here, but it is better to use
our SPtrArray wrapping anyway which fixes the warning as well.

warning: cannot optimize loop, the loop counter may overflow [-Wunsafe-loop-optimizations]
   delete[] Dsc;

Git-Dch: Ignore
Reported-By: gcc -Wunsafe-loop-optimizations