Update libcontainer to 55430d0db7c6bb1198c0bb573a9

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Update mount struct with reference

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Merge pull request #7830 from crosbymichael/update-libcontainer-sep1

Update libcontainer to version 55430d0db7c6bb1198c0bb573a9700a859d5ec26