exec: add parameter errp to qemu_ram_alloc and qemu_ram_alloc_from_ptr Add parameter errp to qemu_ram_alloc and qemu_ram_alloc_from_ptr so that we can handle errors. Signed-off-by: Hu Tao <hutao@cn.fujitsu.com> Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com> [Assert ptr != NULL in memory_region_init_ram_ptr. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>