ocfs2: Remove EXIT from masklog.

mlog_exit is used to record the exit status of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

This patch just try to remove it or change it. So:
1. if all the error paths already use mlog_errno, it is just removed.
   Otherwise, it will be replaced by mlog_errno.
2. if it is used to print some return value, it is replaced with
   mlog(0,...).
mlog_exit_ptr is changed to mlog(0.
All those mlog(0,...) will be replaced with trace events later.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>

fs/ocfs2/dlm/dlmrecovery.c

@@ -727,7 +727,6 @@ static int dlm_remaster_locks(struct dlm_ctxt *dlm, u8 dead_node)
 	if (destroy)
 		dlm_destroy_recovery_area(dlm, dead_node);
 
-	mlog_exit(status);
 	return status;
 }
 
@@ -1496,9 +1495,9 @@ leave:
 			kfree(buf);
 		if (item)
 			kfree(item);
+		mlog_errno(ret);
 	}
 
-	mlog_exit(ret);
 	return ret;
 }
 
@@ -1567,7 +1566,6 @@ leave:
 		dlm_lockres_put(res);
 	}
 	kfree(data);
-	mlog_exit(ret);
 }
 
 
@@ -1986,7 +1984,6 @@ leave:
 			dlm_lock_put(newlock);
 	}
 
-	mlog_exit(ret);
 	return ret;
 }