ocfs2: make mlog_errno return the errno

ocfs2 does

        mlog_errno(v);
        return v;

in many places.  Change mlog_errno() so we can do

        return mlog_errno(v);

For some weird reason this patch reduces the size of ocfs2 by 6k:

  akpm3:/usr/src/25> size fs/ocfs2/ocfs2.ko
     text    data     bss     dec     hex filename
  1146613   82767  832192 2061572  1f7504 fs/ocfs2/ocfs2.ko-before
  1140857   82767  832192 2055816  1f5e88 fs/ocfs2/ocfs2.ko-after

[dan.carpenter@oracle.com: double evaluation concerns in mlog_errno()]
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: alex chen <alex.chen@huawei.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/cluster/masklog.h

@@ -196,13 +196,14 @@ extern struct mlog_bits mlog_and_bits, mlog_not_bits;
 	}								\
 } while (0)
 
-#define mlog_errno(st) do {						\
+#define mlog_errno(st) ({						\
 	int _st = (st);							\
 	if (_st != -ERESTARTSYS && _st != -EINTR &&			\
 	    _st != AOP_TRUNCATED_PAGE && _st != -ENOSPC &&		\
 	    _st != -EDQUOT)						\
 		mlog(ML_ERROR, "status = %lld\n", (long long)_st);	\
-} while (0)
+	_st;								\
+})
 
 #define mlog_bug_on_msg(cond, fmt, args...) do {			\
 	if (cond) {							\