xbps_handle_alloc: use calloc to avoid using unitilizated value.
xbps_handle_alloc: use calloc to avoid using unitilizated value.

datenwolf/xbps,ebfe/xbps,stpx/xbps,ebfe/xbps,datenwolf/xbps,datenwolf/xbps,stpx/xbps,stpx/xbps,ebfe/xbps