K 10
svn:author
V 6
royger
K 8
svn:date
V 27
2020-05-28T08:20:16.796822Z
K 7
svn:log
V 336
xen/control: short circuit xctrl_on_watch_event on spurious event

If there's no data to read from xenstore short-circuit
xctrl_on_watch_event to return early, there's no reason to continue
since the lack of data would prevent matching against any known event
type.

Sponsored by:	Citrix Systems R&D
MFC with:	r352925
MFC after:	1 week

END