[modules] For explicit module file dependencies, only list direct dependency module files.

llvm-svn: 244931
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
index ec47781..c5c3449 100644
--- a/clang/lib/Frontend/DependencyFile.cpp
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -486,6 +486,6 @@
 
 void DFGASTReaderListener::visitModuleFile(llvm::StringRef Filename,
                                            serialization::ModuleKind Kind) {
-  if (Parent.includeModuleFiles() || Kind == serialization::MK_ExplicitModule)
+  if (Parent.includeModuleFiles())
     Parent.AddFilename(Filename);
 }