Pass check_ip and not hostname.ip to _ComputeNics
Pass check_ip and not hostname.ip to _ComputeNics

This should be done because in the case of --no-name-check there
is no 'hostname.ip' attribute, causing an execution error.
'check_ip' is always set (in CheckArguments) even if --no-name-check
is passed in the command line.

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

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