fs: reorder struct inotify_device on 64bits to remove padding

Reorder struct inotify_device to remove 8 bytes of padding on 64bit
builds, reducing size to 128 bytes . Therefore allocating from a smaller
slab & using one fewer cachelines.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>

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Hi,
patch against 2.6.28-rc7.
built & tested on AMDX2 desktop.

I've not been able to send this to the listed inotify maintainers, I
just get mail failures. So I guessed filesystem was the best home for
it, hope that's ok.

regards
Richard
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>