[flang][runtime] Fix ENDFILE for formatted stream output

[klausler]

Summary

A predicate expression made ENDFILE statements significant
only for sequential files, but it's applicable to formatted
stream output as well.

[clementval]

LGTM

flang/runtime/unit.cpp

 }
 
 void ExternalFileUnit::DoEndfile(IoErrorHandler &handler) {
-  if (access == Access::Sequential) {
+  if (IsRecordFile()) {
     endfileRecordNumber = currentRecordNumber;
   }
   FlushOutput(handler);