knfsd: nfsd4: fix NFSv4 filehandle size units confusion

knfsd: nfsd4: fix NFSv4 filehandle size units confusion

NFS4_FHSIZE is measured in bytes, not 4-byte words, so much more space than
necessary is being allocated for struct nfs4_cb_recall.

I should have wondered why this structure was so much larger than it needed to
be!

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>