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/resize.c

@@ -82,7 +82,6 @@ static u16 ocfs2_calc_new_backup_super(struct inode *inode,
 		backups++;
 	}
 
-	mlog_exit_void();
 	return backups;
 }
 
@@ -176,7 +175,8 @@ out_rollback:
 		le16_add_cpu(&group->bg_free_bits_count, -1 * num_bits);
 	}
 out:
-	mlog_exit(ret);
+	if (ret)
+		mlog_errno(ret);
 	return ret;
 }
 
@@ -375,7 +375,6 @@ out_mutex:
 	iput(main_bm_inode);
 
 out:
-	mlog_exit_void();
 	return ret;
 }
 
@@ -585,6 +584,5 @@ out_mutex:
 	iput(main_bm_inode);
 
 out:
-	mlog_exit_void();
 	return ret;
 }