[C++] Use 'nullptr'. Tools edition.

llvm-svn: 207176
diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 4cd3393..ab89832 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -652,7 +652,8 @@
   std::string FullSymbolName(SymbolName);
   if (Symbol.isDynamic()) {
     bool IsDefault;
-    ErrorOr<StringRef> Version = Obj->getSymbolVersion(0, &*Symbol, IsDefault);
+    ErrorOr<StringRef> Version = Obj->getSymbolVersion(nullptr, &*Symbol,
+                                                       IsDefault);
     if (Version) {
       FullSymbolName += (IsDefault ? "@@" : "@");
       FullSymbolName += *Version;