libxl: events: Do not abort remus with ERROR_TIMEOUT

libxl: events: Do not abort remus with ERROR_TIMEOUT

When the timeout set for prompting the next remus iteration fires, we
should not treat the ERROR_TIMEDOUT as an error.

Bug in 31c836f4 "libxl: events: Permit timeouts to signal ao abort".

Reported-by: Yang Hongyang <yanghy@cn.fujitsu.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Yang Hongyang <yanghy@cn.fujitsu.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Yang Hongyang <yanghy@cn.fujitsu.com>