[BPI] Fix memory leak reported by sanitizer bots

[ebrevnov]

Summary

There is a silly mistake where release() is used instead of reset() for free resources of unique pointer.

llvm/lib/Analysis/BranchProbabilityInfo.cpp

for (auto BB : post_order(&F.getEntryBlock())) {
     if (calcZeroHeuristics(BB, TLI))
       continue;
     if (calcFloatingPointHeuristics(BB))
       continue;
   }
 
   PostDominatedByUnreachable.clear();
   PostDominatedByColdCall.clear();
-  SccI.release();
+  SccI.reset();
 
   if (PrintBranchProb &&
       (PrintBranchProbFuncName.empty() ||
        F.getName().equals(PrintBranchProbFuncName))) {
     print(dbgs());
   }
 }