Bluetooth: Fix hci_sync missing wakeup interrupt

__hci_cmd_sync_ev(), __hci_req_sync() could miss wake_up_interrupt from
hci_req_sync_complete() because hci_cmd_work() workqueue and its response
could be completed before they are ready to get the signal through
add_wait_queue(), set_current_state(TASK_INTERRUPTIBLE).

Signed-off-by: Chan-yeol Park <chanyeol.park@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>