[scan-build] fix logic error warning emitted on compiler-rt code base

Summary:
Fix a "called c++ object pointer is null" warning emitted by Clang
Static Analyzer on the following file:
- lib/asan/asan_suppressions.cc.

Signed-off-by: Apelete Seketeli <apelete@seketeli.net>

Reviewers: kcc

Subscribers: Eugene.Zelenko, kubabrecka, llvm-commits

Differential Revision: http://reviews.llvm.org/D19627

llvm-svn: 268282

compiler-rt/lib/asan/asan_suppressions.cc

@@ -89,6 +89,7 @@ bool IsStackTraceSuppressed(const StackTrace *stack) {
 
     if (suppression_ctx->HasSuppressionType(kInterceptorViaFunction)) {
       SymbolizedStack *frames = symbolizer->SymbolizePC(addr);
+      CHECK(frames);
       for (SymbolizedStack *cur = frames; cur; cur = cur->next) {
         const char *function_name = cur->info.function;
         if (!function_name) {