fs: inode - remove 8 bytes of padding on 64bits allowing 1 more objects/slab under slub

This removes 8 bytes of padding from struct inode on 64bit builds, and
so allows 1 more object/slab in the inode_cache when using slub.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against 2.6.33-rc8
compiled & tested on x86_64 AMDX2

I've been running this patch for over a week with no obvious problems
regards
Richard
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/linux/fs.h

@@ -729,6 +729,7 @@ struct inode {
 	uid_t			i_uid;
 	gid_t			i_gid;
 	dev_t			i_rdev;
+	unsigned int		i_blkbits;
 	u64			i_version;
 	loff_t			i_size;
 #ifdef __NEED_I_SIZE_ORDERED
@@ -738,7 +739,6 @@ struct inode {
 	struct timespec		i_mtime;
 	struct timespec		i_ctime;
 	blkcnt_t		i_blocks;
-	unsigned int		i_blkbits;
 	unsigned short          i_bytes;
 	umode_t			i_mode;
 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */