Use softtabstop instead of redefining tabstop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61618 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/vim/vimrc b/utils/vim/vimrc
index c400a13..e57c221 100644
--- a/utils/vim/vimrc
+++ b/utils/vim/vimrc
@@ -14,7 +14,7 @@
 set textwidth=80
 
 " A tab produces a 2-space indentation
-set tabstop=2
+set softtabstop=2
 set shiftwidth=2
 set expandtab