xen/time: use READ_ONCE

Use READ_ONCE through the code, rather than explicit barriers.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
1 file changed