BLE Secuity manager state machine generate wrong pairing success event.

 we call smp_proc_release_delay to setup a timer.
We will send a pair failure message to uplayer after the time expired.
Right before the time expire, the l2cap connection is disconnected
from remote device, we receive L2C_DISC, which will call smp_delay_terminate,
 smp_delay_terminate will send a pair success message to uplayer.
The fix is not to change the status if the remote device disconnect the link

bug:11716967
Change-Id: I8ca63599a170ec86913785aafea552301cec37df