Make getObject const. Remove a const_cast.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178980 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-readobj/MachODumper.cpp b/tools/llvm-readobj/MachODumper.cpp
index 0354e76..006158e 100644
--- a/tools/llvm-readobj/MachODumper.cpp
+++ b/tools/llvm-readobj/MachODumper.cpp
@@ -254,7 +254,7 @@
 
     ++SectionIndex;
 
-    const MachOObject *MachO = const_cast<MachOObjectFile*>(Obj)->getObject();
+    const MachOObject *MachO = Obj->getObject();
 
     MachOSection Section;
     getSection(MachO, SecI->getRawDataRefImpl(), Section);