vfio/container: Fix SIGSEGV when open container file fails

When open /dev/vfio/vfio fails, SIGSEGV triggers because
vfio_listener_unregister() doesn't support a NULL bcontainer
pointer.

Fixes: a1f267a7d4d9 ("vfio/container: reform vfio_container_connect cleanup")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250623102235.94877-2-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
1 file changed