[clangd][nfc] Correct header name in comment

llvm-svn: 328149
diff --git a/clang-tools-extra/clangd/index/Index.h b/clang-tools-extra/clangd/index/Index.h
index 1b752b67..42f23ce 100644
--- a/clang-tools-extra/clangd/index/Index.h
+++ b/clang-tools-extra/clangd/index/Index.h
@@ -1,4 +1,4 @@
-//===--- Symbol.h -----------------------------------------------*- C++-*-===//
+//===--- Index.h ------------------------------------------------*- C++-*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //