GetAllInstancesInfo, change internal iterator name
GetAllInstancesInfo, change internal iterator name

GetAllInstancesInfo used "node" as an iterator name. Change it to
instance to make it less confusing.

Reviewed-by: iustinp


yiannist/ganeti,grnet/snf-ganeti,bitemyapp/ganeti,ganeti-github-testing/ganeti-test-1,leshchevds/ganeti,dimara/ganeti,apyrgio/snf-ganeti,dimara/ganeti,apyrgio/ganeti,mbakke/ganeti,mbakke/ganeti,andir/ganeti,ganeti/ganeti,apyrgio/snf-ganeti,apyrgio/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,leshchevds/ganeti,leshchevds/ganeti,andir/ganeti,ganeti/ganeti,andir/ganeti,yiannist/ganeti,bitemyapp/ganeti,grnet/snf-ganeti,ganeti/ganeti,onponomarev/ganeti,mbakke/ganeti,onponomarev/ganeti