Pass qemu_sglist_init the global dma_context_memory rather than a NULL
pointer; this fixes a segfault in dma_memory_map() when the guest
starts using DMA.
Reported-by: Amadeusz Sławiński <amade@asmblr.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>