Revert "[tools] Updating PPCallbacks::InclusionDirective calls"

This reverts commit r331905, since it's dependent on reverted r331905.

llvm-svn: 331931
diff --git a/clang-tools-extra/clangd/ClangdUnit.cpp b/clang-tools-extra/clangd/ClangdUnit.cpp
index fd8f1ec..c750f57 100644
--- a/clang-tools-extra/clangd/ClangdUnit.cpp
+++ b/clang-tools-extra/clangd/ClangdUnit.cpp
@@ -93,8 +93,7 @@
                           StringRef FileName, bool IsAngled,
                           CharSourceRange FilenameRange, const FileEntry *File,
                           StringRef SearchPath, StringRef RelativePath,
-                          const Module *Imported,
-                          SrcMgr::CharacteristicKind FileType) override {
+                          const Module *Imported) override {
     auto SR = FilenameRange.getAsRange();
     if (SR.isInvalid() || !File || File->tryGetRealPathName().empty())
       return;