Revert r184249, "doc. parsing: Allow parameter name "..." for variadic functions/methods."

It crashes in the case;

/// Without any "param"s in the description.
int printf(const char *format, ...);

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184283 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a warning. [-Wunused-variable]

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184284 91177308-0d34-0410-b5e6-96231b3b80d8