[NFC][MemDep] Remove unnecessary Worklist.clear

This execution path leads to return 'false' where the Worklist
will be deallocated anyways. No need to clear it separately.

llvm/lib/Analysis/MemoryDependenceAnalysis.cpp

@@ -1195,7 +1195,6 @@ bool MemoryDependenceResults::getNonLocalPointerDepFromBB(
     // If we do process a large number of blocks it becomes very expensive and
     // likely it isn't worth worrying about
     if (Result.size() > NumResultsLimit) {
-      Worklist.clear();
       // Sort it now (if needed) so that recursive invocations of
       // getNonLocalPointerDepFromBB and other routines that could reuse the
       // cache value will only see properly sorted cache arrays.