As standard mount.Unmount does what we need, let's use it. In addition, this adds ignoring "not mounted" condition, which was previously implemented (see PR#33329, commit cfa2591d3f26) via a very expensive call to mount.Mounted(). Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> (cherry picked from commit 77bc327e24a60791fe7e87980faf704cf7273cf9) Upstream-commit: 893b24b80db170279d5c9532ed508a81c328de5e Component: engine