ext3: kill 2 useless magic numbers

dx_root_limit() will never return 20, and I can't figure out what 20
stands for.  This function has never changed since htree directory
indexing was merged.

Similar for dx_node_limit() and the magic 22.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ext3/namei.c

@@ -240,13 +240,13 @@ static inline unsigned dx_root_limit (struct inode *dir, unsigned infosize)
 {
 	unsigned entry_space = dir->i_sb->s_blocksize - EXT3_DIR_REC_LEN(1) -
 		EXT3_DIR_REC_LEN(2) - infosize;
-	return 0? 20: entry_space / sizeof(struct dx_entry);
+	return entry_space / sizeof(struct dx_entry);
 }
 
 static inline unsigned dx_node_limit (struct inode *dir)
 {
 	unsigned entry_space = dir->i_sb->s_blocksize - EXT3_DIR_REC_LEN(0);
-	return 0? 22: entry_space / sizeof(struct dx_entry);
+	return entry_space / sizeof(struct dx_entry);
 }
 
 /*