Staging: hv: Use native wait primitives

In preperation for getting rid of the osd layer; change
the code to use native wait interfaces. As part of this,
fixed the buggy implementation in the osd_wait_primitive
where the condition was cleared potentially after the
condition was signalled.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>