Bluetooth: Fix sending unnecessary HCI_Write_SSP_Mode command

This patch fixes sending an unnecessary HCI_Write_SSP_Mode command if
the command has already been sent as part of the default HCI init
sequence.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>