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

llvm-svn: 207176
diff --git a/llvm/tools/llvm-extract/llvm-extract.cpp b/llvm/tools/llvm-extract/llvm-extract.cpp
index 2e5a2af..4131177 100644
--- a/llvm/tools/llvm-extract/llvm-extract.cpp
+++ b/llvm/tools/llvm-extract/llvm-extract.cpp
@@ -103,7 +103,7 @@
   std::unique_ptr<Module> M;
   M.reset(getLazyIRFileModule(InputFilename, Err, Context));
 
-  if (M.get() == 0) {
+  if (!M.get()) {
     Err.print(argv[0], errs());
     return 1;
   }