libxl_domain_unpause needs to make QMP calls, which are asynchronous,
change the API to reflect that.
Do the same with libxl_domain_pause async, even if it will keep
completing synchronously.
Also fix some coding style issue in those functions.
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>