NFS: Don't clear nfsi->cache_validity in nfs_check_inode_attributes()

If we're merely checking the inode attributes because we suspect that the
'updated' attributes returned by the RPC call are stale, then we shouldn't
be doing weak cache consistency updates or clearing the cache_validity
flags.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --cc fs/nfs/inode.c
Simple merge