otafault: Fix setting of have_eio_error.

There was one case (ota_fsync, under TARGET_SYNC_FAULT, when the
filename was cached) where we were not setting have_eio_error
prior to returning.  We fix that.

Change-Id: I2b0aa61fb1e821f0e77881aba04db95cd8396812

otafault/ota_io.cpp

@@ -189,8 +189,8 @@ int ota_fsync(int fd) {
             && FilenameCache[fd] == FaultFileName) {
         FaultFileName = "";
         errno = EIO;
-        return -1;
         have_eio_error = true;
+        return -1;
     } else {
         int status = fsync(fd);
         if (status == -1 && errno == EIO) {