[Coverity][Graph] Wrapper escape reports in graph code

[Bensuo]

See issues at https://scan.coverity.com/projects/intel-llvm?tab=overview

Two WRAPPER_ESCAPE issues have been reported in SYCL graph code on Coverity:

CID 516777

llvm/sycl/source/detail/graph_impl.cpp

Line 94 in e22b8e4

SortedNodes.push_back(Node);

CID 524576

llvm/sycl/source/detail/graph_memory_pool.cpp

Line 152 in e22b8e4

if (CurrentNode->MTotalVisitedEdges > 0) {