Attempt to fix buildbot.

llvm-svn: 266799
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 0b69bea..bd239d4 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -105,7 +105,7 @@
   }
   if (Op == "&")
     return L & R;
-  llvm_unreachable("unknown operator " + Op);
+  llvm_unreachable("invalid operator");
   return 0;
 }