llvm-readobj: call exit(1) on error.

llvm-readobj exists for testing llvm. We can safely stop the program
the first time we know the input in corrupted.

This is in preparation for making it handle a few more broken files.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242656 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-readobj/llvm-readobj.h

@@ -19,7 +19,7 @@ namespace llvm {
   }
 
   // Various helper functions.
-  bool error(std::error_code ec);
+  void error(std::error_code ec);
   bool relocAddressLess(object::RelocationRef A,
                         object::RelocationRef B);
 } // namespace llvm