container_create_linux: refactor common code
container_create_linux: refactor common code

use a map to keep track of the different mode used by each mount when
running as readonly.

Signed-off-by: Giuseppe Scrivano <20002b7b24c75512093a71a58285826d5c504fca@redhat.com>

nalind/cri-o,nalind/cri-o,kubernetes-incubator/ocid,mikebrow/cri-o,kubernetes-incubator/ocid,kubernetes-incubator/cri-o,mikebrow/cri-o,mikebrow/cri-o,kubernetes-incubator/cri-o,nalind/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/ocid,mikebrow/cri-o