Fix acquisition of node lock in LUInstanceGrowDisk
Fix acquisition of node lock in LUInstanceGrowDisk

Ensure node level locks are recalculated properly
in LUInstanceGrowDisk.

Signed-off-by: Constantinos Venetsanopoulos <5aa4b75752c9a2933cd7300cda758def9255d1ca@grnet.gr>
Signed-off-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>
Reviewed-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>

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