Revert "[ThinLTO] Renaming of function index to module summary index (NFC)"

This reverts commit r263490. Missed a file.

llvm-svn: 263493

llvm/test/Bitcode/thinlto-function-summary-refgraph.ll

@@ -1,5 +1,5 @@
 ; Test to check both the callgraph and refgraph in summary
-; RUN: llvm-as -module-summary %s -o %t.o
+; RUN: llvm-as -function-summary %s -o %t.o
 ; RUN: llvm-bcanalyzer -dump %t.o | FileCheck %s
 
 ; See if the calls and other references are recorded properly using the