Control: fanctl should validate dumpfile output

fanctl is emitting "done" messages prematurely before all file contents
have been written. This change erases any existing json outputs and
proactively validates the output before reporting success.

Signed-off-by: Mike Capps <mikepcapps@gmail.com>
Change-Id: I364024675a468bc0dfb1035e3158e85c206b79d2
1 file changed