chassishandler: Refactor get/set boot parameters code

-Make use of 'getDbusProperty'/'setDbusProperty' library functions
-Remove duplicate log messages on errors

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Change-Id: Iadd3b145b2170667ca0d885a6413d1ef86b6fe27
1 file changed