Having creation as a member of the CharDriver struct removes the need
to export functions for qemu-char.c's usage. After the conversion,
chardev backends implemented outside qemu-char.c will not need a stub
creation function anymore.
Ultimately all drivers will be converted. For now, support the case
where cd->create == NULL.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
4ca172817a