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>