Fix Cdma conference cleanup bug.

The conference pointer in the CdmaConferenceController wasn't being cleared after the
conference was destroyed.  This prevented subsequent conferences from being created
correctly (ie. couldn't merge calls into a new conference).

Bug: 19355781, 18612712
Change-Id: I0612d7e2f89cdb56ed330289d08ee4e7ef007970
1 file changed