Remove test of command reply status as it is already performed by
__hci_cmd_sync().
__hci_cmd_sync_ev() function already returns an error if it got a
non-zero status either through a Command Complete or a Command
Status event.
For both of these events the status is collected up in the event
handlers called by hci_event_packet() and then passed as the second
parameter to req_complete_skb(). The req_complete_skb() callback in
turn is hci_req_sync_complete() for __hci_cmd_sync_ev() which stores
the status in hdev->req_result. The hdev->req_result is then further
converted through bt_to_errno() back in __hci_cmd_sync_ev().