Fix two recently introduced compile problems:

Fix a typo in fs/nfs/pnfs.h

Move the pnfs_blksize declaration outside the CONFIG_NFS_V4 section in
struct nfs_server.
Reported-by: NJens Axboe <jaxboe@fusionio.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>