Add missing description to llvm-remarkutil doc header

Doc builder caught this:

```
File ".../llvm/src/llvm/docs/conf.py", line 271, in process_rst
name,description = title.split(' - ', 1)
ValueError: not enough values to unpack (expected 2, got 1)
```

diff --git a/llvm/docs/CommandGuide/LLVMRemarkUtil.rst b/llvm/docs/CommandGuide/LLVMRemarkUtil.rst
index b068dc3..141ba42 100644 (file)
--- a/llvm/docs/CommandGuide/LLVMRemarkUtil.rst
+++ b/llvm/docs/CommandGuide/LLVMRemarkUtil.rst
@@ -1,4 +1,4 @@
-llvm-remarkutil -
+llvm-remarkutil - Remark utility
 ==============================================================
 
 .. program:: llvm-remarkutil