BugLink: https://bugs.launchpad.net/bugs/1774181

The original embargoed patches introduced an arch-specific barrier macro
gmb() (later renamed to osb()) which is used to prevent speculation beyond
array boundaries. What finally landed in upstream is an arch-agnostic
masking solution in favor of osb(). In Ubuntu, we still use osb() in a
couple of places where upstream does nothing, so change those to using the
masking solution.
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>