ciao-down: Delay checking for Nested VM support after flag parsing
ciao-down: Delay checking for Nested VM support after flag parsing

We want to able to access the help at any point, so defer the nested VM
check until after the flag parsing.

Today, ciao-down can print the nested VM error and exit before it has
the change to print the help.

Updates: https://github.com/01org/ciao/issues/1351
Signed-off-by: Damien Lespiau <64bd3cb94f359c1a3ce68dae5e26b40578526277@intel.com>

markdryan/ciao,markdryan/ciao,rbradford/ciao,mcastelino/ciao,kaccardi/ciao,tpepper/ciao,mcastelino/ciao,rbradford/ciao,01org/ciao,ciao-project/ciao,ciao-project/ciao,tpepper/ciao,kaccardi/ciao,mcastelino/ciao,tpepper/ciao,01org/ciao