COFF: Fix memory leak.

llvm-svn: 239272
diff --git a/lld/COFF/InputFiles.cpp b/lld/COFF/InputFiles.cpp
index 62bb144..5948a2c 100644
--- a/lld/COFF/InputFiles.cpp
+++ b/lld/COFF/InputFiles.cpp
@@ -187,7 +187,7 @@
 SymbolBody *ObjectFile::createSymbolBody(StringRef Name, COFFSymbolRef Sym,
                                          const void *AuxP, bool IsFirst) {
   if (Sym.isUndefined())
-    return new Undefined(Name);
+    return new (Alloc) Undefined(Name);
   if (Sym.isCommon()) {
     Chunk *C = new (Alloc) CommonChunk(Sym);
     Chunks.push_back(C);