Checks the SMP length to fix OOB read

Bug: 111937065
Test: manual
Change-Id: I330880a6e1671d0117845430db4076dfe1aba688
Merged-In: I330880a6e1671d0117845430db4076dfe1aba688
(cherry picked from commit fceb753bda651c4135f3f93a510e5fcb4c7542b8)

void smp_br_pairing_complete(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) {
  SMP_TRACE_DEBUG("%s", __func__);

 if (p_cb->total_tx_unacked == 0) {
 /* process the pairing complete */
    smp_proc_pairing_cmpl(p_cb);
 }
}

void smp_br_pairing_complete(tSMP_CB* p_cb, tSMP_INT_DATA* p_data) {
  SMP_TRACE_DEBUG("%s", __func__);

 if (p_cb->total_tx_unacked == 0) {
 /* process the pairing complete */
    smp_proc_pairing_cmpl(p_cb);
 }
}
