[docs] Add ellipsis.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176810 91177308-0d34-0410-b5e6-96231b3b80d8

docs/UsersManual.rst

@@ -828,7 +828,7 @@ Controlling Code Generation
 Clang provides a number of ways to control code generation. The options
 are listed below.
 
-**-fsanitize=check1,check2**
+**-fsanitize=check1,check2,...**
    Turn on runtime checks for various forms of undefined or suspicious
    behavior.