tools/blktap2: fix build errors caused by Werror in

vhd_journal_write_entry

-O2 -Wall -Werror triggers these warnings:

libvhd-journal.c: In function 'vhd_journal_write_entry':
libvhd-journal.c:335: warning: statement with no effect

Really return the error from vhd_journal_write() to caller.

v2:
 - simplify the patch by just adding the missing return statement

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Committed-by: Keir Fraser <keir@xen.org>

tools/blktap2/vhd/lib/libvhd-journal.c

@@ -332,7 +332,7 @@ vhd_journal_write_entry(vhd_journal_t *j, vhd_journal_entry_t *entry)
 
 	err = vhd_journal_write(j, &e, sizeof(vhd_journal_entry_t));
 	if (err)
-		err;
+		return err;
 
 	return 0;
 }