Merge changes I228ee25f,I85914c62,I3a5c970d,I5f54b858,I6a885f21, ...

* changes:
  report_dup is always true
  Remove useless states
  Flatten btm_set_inq_event_filter
  pending_filt_complete_event is always zero
  inqfilt_active is always false
  Setting inqfilt_active to true has no effect
  p_inq->state is always BTM_INQ_SET_FILT_STATE when calling
  inqfilt_active is always true inside btm_set_inq_event_filter
  Status is always success
  p_inqfilter_cmpl_cb is never set
  hci_status is always success
  We never set the inquiry filter
  btm_set_inq_event_filter always returns CMD_STARTED