Silence an ambiguous else warning from GCC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112809 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/PBQP/HeuristicBase.h

@@ -173,12 +173,13 @@ namespace PBQP {
       bool finished = false;
 
       while (!finished) {
-        if (!optimalReduce())
+        if (!optimalReduce()) {
           if (impl().heuristicReduce()) {
             getSolver().recordRN();
           } else {
             finished = true;
           }
+        }
       }
     }