control:fanctl: `dump` option only for JSON

Only show the `dump` option when the use of JSON is enabled. There is no
support for creating a fan control dump of the flight recorder, etc.. in
YAML based fan control configurations.

Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
Change-Id: I7602fb4f45441058831a023a8d62dbecaf94574b
1 file changed