Controller: Fix command description reference

There's a bug in handling command description 'desc' parameter. Code
references variable 'desc' but instead we have to use 'desc' key of
command dictionary.

Signed-off-by: Jan Tluka <jtluka@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
TaskAPI: Add command description to host.run args

This patch adds 'desc' argument into HostAPI's run method.

Signed-off-by: Jan Tluka <jtluka@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>