Fix more 'cpo' issues in runtime files.
diff --git a/runtime/indent/cmake.vim b/runtime/indent/cmake.vim
index 8c408fb..421afcb 100644
--- a/runtime/indent/cmake.vim
+++ b/runtime/indent/cmake.vim
@@ -23,6 +23,8 @@
 if exists("*CMakeGetIndent")
   finish
 endif
+let s:keepcpo= &cpo
+set cpo&vim
 
 fun! CMakeGetIndent(lnum)
   let this_line = getline(a:lnum)
@@ -83,3 +85,6 @@
 
   return ind
 endfun
+
+let &cpo = s:keepcpo
+unlet s:keepcpo