Bluetooth: A2MP: Fix not initializing all members

commit eddb7732119d53400f48a02536a84c509692faa8 upstream.

This fixes various places where a stack variable is used uninitialized.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>