[llvm-readobj] - An attemp to fix BB after r369191.

Few BB failed with the following error:

Command Output (stderr):
--
/home/buildbots/ppc64be-clang-lnt-test/clang-ppc64be-lnt/llvm/test/tools/llvm-readobj/stack-sizes.test:263:19: error: BADSECTION-OUT: expected string not found in input
# BADSECTION-OUT: 8 ?
                  ^
<stdin>:4:1: note: scanning from here

^

It doesn't reproduce on ubuntu/windows I have. Also, seems many of the bots
are happy too.

This slightly reorders the code to make fouts().flush() call earlier,
like it was before the r369191.

llvm-svn: 369192

llvm/tools/llvm-readobj/llvm-readobj.cpp

@@ -395,14 +395,14 @@ LLVM_ATTRIBUTE_NORETURN void reportError(Error Err, StringRef Input) {
 
 void reportWarning(Error Err, StringRef Input) {
   assert(Err);
+  // Flush the standard output to print the warning at a
+  // proper place.
+  fouts().flush();
   if (Input == "-")
     Input = "<stdin>";
 
   handleAllErrors(createFileError(Input, std::move(Err)),
                   [&](const ErrorInfoBase &EI) {
-                    // Flush the standard output to print the warning at a
-                    // proper place.
-                    fouts().flush();
                     errs() << "\n";
                     WithColor::warning(errs()) << EI.message() << "\n";
                   });