[C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.

llvm-svn: 206252
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index ce4b3d5..d0a56aa 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -420,7 +420,8 @@
                                  bool Is64bits, error_code &EC,
                                  bool BufferOwned)
     : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object, BufferOwned),
-      SymtabLoadCmd(NULL), DysymtabLoadCmd(NULL), DataInCodeLoadCmd(NULL) {
+      SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr),
+      DataInCodeLoadCmd(nullptr) {
   uint32_t LoadCommandCount = this->getHeader().ncmds;
   MachO::LoadCommandType SegmentLoadType = is64Bit() ?
     MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT;