virtio-blk: fix cross-endianness targets virtio-blk doesn't work on cross-endian configuration, as endianness is not handled correctly. This patch adds missing endianness conversions to make virtio-blk working. Tested on the following configurations: - i386 guest on x86_64 host - ppc guest on x86_64 host - i386 guest on mips host - ppc guest on mips host Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>