Adding MiFARE DESFire format support

Fix semantic error when deregister P2P if discovery has started

This patch is to disable discovery before deregister P2P and re-enable discovery after that.

Code inspection fixes

Remove unused class memeber and avoid variable uninitialized.

Change-Id: I2da3a37c98de3e4f36cfcd1061d060ef14f4e00a
(cherry picked from commit 38be878b6f068634ea53ab6ccf6b336acd42ec97)