Use a reference instead of a pointer.

This makes using a std::unique_ptr in the caller more convenient.

llvm-svn: 214433
diff --git a/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp b/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
index 630f629..7c4743b 100644
--- a/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
+++ b/llvm/tools/llvm-symbolizer/LLVMSymbolize.cpp
@@ -388,7 +388,7 @@
     Modules.insert(make_pair(ModuleName, (ModuleInfo *)nullptr));
     return nullptr;
   }
-  DIContext *Context = DIContext::getDWARFContext(DbgObj);
+  DIContext *Context = DIContext::getDWARFContext(*DbgObj);
   assert(Context);
   ModuleInfo *Info = new ModuleInfo(Obj, Context);
   Modules.insert(make_pair(ModuleName, Info));