Restore the -llvm option


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9915 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-dis/llvm-dis.cpp b/tools/llvm-dis/llvm-dis.cpp
index 8d0ca7b..d035b7f 100644
--- a/tools/llvm-dis/llvm-dis.cpp
+++ b/tools/llvm-dis/llvm-dis.cpp
@@ -47,7 +47,7 @@
 
 static cl::opt<enum OutputMode>
 WriteMode(cl::desc("Specify the output format:"),
-          cl::values(clEnumVal(LLVM, "Output LLVM assembly"),
+          cl::values(clEnumValN(LLVM, "llvm", "Output LLVM assembly"),
                      clEnumVal(c, "Output C code for program"),
                     0));