MDEV-17482 InnoDB fails to say which fatal error fsync() returned

os_file_fsync_posix(): If fsync() returns a fatal error,
do include errno in the error message.

In the future, we might handle fsync() or write or allocation failures
on InnoDB data files a little more gracefully: flag the affected index
or table as corrupted, and deny any subsequent writes to the table.

If a write to the undo log or redo log fails, an alternative to
killing the server could be to deny any writes to InnoDB tables
until the server has been restarted.

storage/innobase/os/os0file.cc

@@ -2495,18 +2495,10 @@ os_file_fsync_posix(
 			ut_a(failures < 2000);
 			break;
 
-		case EIO:
-			ib::error() << "fsync() returned EIO, aborting";
-			/* fall through */
 		default:
-			ut_error;
-			break;
+			ib::fatal() << "fsync() returned " << errno;
 		}
 	}
-
-	ut_error;
-
-	return(-1);
 }
 
 /** Check the existence and type of the given file.